幼鼠骨骼发育中高脂饮食的影响

中国组织工程研究与临床康复第15卷第7期 2011–02–12出版

Journal of Clinical Rehabilitative Tissue Engineering Research February 12, 2011 Vol.15, No.7 ISSN 1673-8225 CN 21-1539/R CODEN: ZLKHAH

1321 1Department of Endocrinology, the Affiliated Hospital of Qingdao University Medical College, Qingdao 266003, Shandong Province, China; 2Division of Endocrinology, Diabetes, Bone and Mineral Disorders, Department of Internal Medicine, Henry Ford Hospital, Detroit, MI 48202, USA; 3Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA

Wang Luan★, Master, Attending physician, Department of Endocrinology, the Affiliated Hospital of Qingdao University Medical College, Qingdao 266003, Shandong Province, China

wangluan@yahoo. com

Correspondence to: Yan Sheng-li, Professor, Chief physician, Department of Endocrinology, the Affiliated Hospital of Qingdao University Medical College, Qingdao 266003, Shandong Province, China

yansl07@8e5bddb4376baf1ffd4fad26

Supported by: the National Natural Science Foundation of China, No. 30671005* Received:2010-09-27 Accepted:2010-10-25 (20100901013/YJ) Wang L, Yan SL, Wang F, Mi QS. Effects of a high-fat diet on bone development in young mice. Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu. 2011;15(7):

1321-1326.

[8e5bddb4376baf1ffd4fad26 8e5bddb4376baf1ffd4fad26]

Effects of a high-fat diet on bone development in young mice*★○

Wang Luan1, Yan Sheng-li1, Wang Fang1, Mi Qing-sheng○2, 3

Abstract

BACKGROUND: High fat diet (HFD) can induce overweight and obesity, which have been considered to positively affect bone

mineral density (BMD) in adults. However, it is unclear how HFD affects the bone development during childhood.

OBJECTIVE: To determine the effect of HFD on bone development in young female mice.

METHODS: Twelve female CD1 mice were fed with either HFD or normal fat diet (NFD) starting at 4-week of age for 10 weeks.

The bone mineral content (BMC), BMD, fat and lean mass were examined in 14-week old mice using dual-energy X-ray

absorptiometry, and bone biomechanical properties were also evaluated using three-point bending test. Serum concentration of

bone metabolic markers was measured using enzyme immunoassay. Femora were sectioned in the transverse plane and stained

with hematoxylin and eosin for observing the adiposity of bone marrow and changes in trabecular bone area.

RESULTS AND CONCLUSION: The body weight and fat mass in HFD-treated mice were increased compared with those in

NFD-treated mice, respectively. There were no significant differences between HFD-treated and NFD-treated mice in whole body

BMD, BMC, bone area and lean mass. However, the spine BMC and bone area in HFD mice were significantly lower than that in

NFD mice, while femoral BMD, BMC and bone area in HFD mice were significantly greater than that in NFD mice. But, there was

no statistically different in bone biomechanical values between the two groups. Bone metabolic markers were lower in HFD mice

than NFD mice, indicating the less active of bone metabolism in HFD mice. It is suggested that HFD can produce deleterious

effect on bone during the active growing phase of young mice. Vertebral bone is more sensitive to this negative effect than cortical

bone due to the decreased vertebral mineralization. Weight-bearing bone does not response sufficiently to compensate for the

excessive weight gaining.

INTRODUCTION

The prevalence of overweight and obesity during childhood has substantially increased in recent decades[1]. This increase might be partially attributable to the increasing percentage of high-fat and high-calories diet[2]. The Committee on Nutrition of the American Academy of Pediatrics (AAP) recommended that by 5 years of age, children consume diets with ≤30% of energy from fat and <10% total calories from saturated fatty acids[3]. However, children and adolescents in the United States today consume diets that are rich in fat which accounts 34%-36% of energy intake, which has resulted many health problems among children and adolescence, such as obesity, type 2 diabetes, high blood pressure, etc[1, 4]. It has been observed that childhood obesity is linked to increased risk of forearm fractures[5]. Nevertheless, studies on bone status of obese children obtained the conflicting results[6-9]. Different experimental design, subjects and even analysis models may lead to the contradictory results. However, it is proposed that bone fragility is likely to have its origins established during growth, and bone mass gained during childhood account for about half the bone mass achieved in adulthood[10]. Therefore, it is crucial to clarify the impact of fat and obesity on growing bone. Yet, the human in vivo study is restricted to morphologically evaluation of bone, and is hard to examine the biomechanics of bone which determines the skeletal fragility and bone quality. Thus, in this study, we contrast the influence of high- and normal-fat diet on bone structure and mechanics of young female CD1 mice. MATERIALS AND METHODS

Design

A randomized, controlled, animal study.

Time and setting

This study was performed in Center for Biotechnology and Genomic Medicine, Medical College of Georgia, USA and the Affiliated Hospital of Medical College, Qingdao University, between January and August in 2008.

Animals

A total of 12 CD1 female mice were obtained from Dr. Mi Qing-sheng’s laboratory. In order to minimize the inpidual variance, mice with extremely low or high birth weight were excluded. The average body weight of 4-week old mice before experiment was

(26.69±2.08) g. All experimental procedures were performed in accordance with the guidelines of the Institutional Animal Care and Use Committee of Medical College of Georgia.

Methods

Grouping and intervention

After weaning at 3-week age and adaptive feeding with normal diet for one week, all mice were randomly assigned into normal fat diet (NFD) group or high-fat diet (HFD) group (diet No. F2685, BioServe, Frenchtown, NJ) at age of 4-week. Table 1 shows the ingredients of different diet. The mice had a free access to diet and water. The mice were weighed weekly during the experiment and urine glucose was monitored monthly in HFD mice to exclude the onset

Wang L, et al. Effects of a high-fat diet on bone development in growing mice

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of type 2 diabetes induced by obesity. After 10 weeks of

experiment, all the animals were killed by CO 2 inhalation at 14-week age.

Bone densitometry

Bone mineral density (BMD), bone mineral content (BMC), scanned area, lean and percentage of body fat (% body-fat) were measured by dual-energy X-ray absorptiometry (DEXA) (PIXImus system; GE LUNAR, Madison, WI) before and after 10-week different diets [11]

.

Biomechanical testing Bone biomechanical properties were evaluated using the left femora of NFD and HFD mice for three-point bending test [11]

.

The mechanical resistance to failure was tested using a servo-controlled electromechanical system (Instron, High Wycombe, England). The following parameters were derived

from the force-displacement curve: ① ultimate force (Fu),

representing the strength of bone; ② stiffness (S), calculated as

the slope of the linear portion of the load-displacement curve,

representing elastic deformation; and ③ work to failure (U),

determined as the area under the load-displacement curve,

representing the energy the bone can absorb before breaking.

Biochemical measurements

Blood was obtained before mice were sacrificed at 14-week of

age and serum was extracted for biochemical test. The serum

concentration of pyridinoline crosslinks (PYD) and osteocalcin

were measured using enzyme immunoassay (EIA) kits (Quidel,

San Diego, CA; Biomedical Technologies Inc., USA)[12]

.

Histological determination One femur from each mouse (14-week old) was decalcified in 4% EDTA for 1 week and then processed for routine paraffin embedding following standard procedures [13]

. Femora were sectioned (5 μm) in the transverse plane and stained with hematoxylin and eosin to yield diaphyseal cross-sections used for observing the adiposity of bone marrow and trabecular bone area. Main outcome measures The effects of HFD on bone development including bone density, biomechanics, bone turnover and histological changes were evaluated. Statistical analysis All analyses were performed using SPSS 11.5 software. Raw data were presented as Means±SD and analyzed by independent-samples t -test. General linear model, analysis of

variance was conducted to compare bone measurements

adjusted for body weight and fat mass respectively.

RESULTS

Quantitative analysis of experimental animals

One mouse in the HFD group died because of overdose of anesthetics during testing bone densitometry and was excluded. A total of 12 mice were included in the final analysis, with 6 mice in each group. Characteristics of the mice There was no difference of body characteristics between two groups of mice before HFD. After being fed HFD for 10 weeks, HFD mice developed obvious obesity with dramatically greater

body weight and fat percentage than NFD mice (P < 0.01). Yet, the lean mass in HFD mice was not increased, resulting in the lean mass percentage significantly lower than NFD mice (T able 2). Inconsistent phenotype in femoral and spinal bones HFD mice had higher total body BMD, BMC, bone area and lean mass, but the difference was not statistically significant. Femora of HFD mice presented higher BMD, BMC and bone area than those of NFD mice (P< 0.01 or P < 0.05). In contrast, there was no significant difference in the lumber spine BMD in two groups (P > 0.05), but the BMC and bone area in HFD mice were lower than NFD mice (P < 0.01, Figure 1). When adjusted for body weight or fat mass, the body BMD, BMC, bone area, femur BMD, BMC and femur area tended to be lower in HFD mice in comparison to NFD mice although the difference was not statistically significant (Figure 1). Variation of femoral bone biomechanics The femoral bone mechanical properties of HFD mice were better than NFD mice, but the difference was not significant (Figures 2a, b, c). To further understand the bone quality, we

calculated the ratio of strength and bone density, the difference was also not statistically significant (Figure 2d). Changes of bone metabolic markers The specific bone resorption marker-PYD and bone formation marker-osteocalcin were lower in HFD mice than control, but this reduction was not significant (Figure 3). Histological variation Compared with NFD mice, the number of bone marrow adipocytes was obviously increased and the trabecular bone area reduced in HFD mice, suggesting bone structure had changed (Figure 4).

DISCUSSION Investigating the effect of HFD since very young age on bones,

Wang L, et al. Effects of a high-fat diet on bone development in growing mice

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we found the discrepancy of bone response to HFD-induced obesity. After 10 week HFD, the fat mass of HFD mice increased nearly 2.5 folds, yet the whole body BMD and BMC did not significantly increase corresponding to the fat mass gaining. It is observed lumber BMC, BMD, bone area decreased and femoral BMC, BMD and bone area increased.

The present study showed that HFD could no doubt cause

overweight and obesity in female mice, the absolute lean mass did not differ between groups, but the lean percentage was

significant lower in HFD mice. Hence, HFD-resulted obesity

mainly caused by the increasing of body fat mass, which determined bone status in this study. After adjustment for fat mass, the total body BMD and BMC even tended to be lower than NFD mice, suggesting that fat mass is poorly contributes to bone mineralization. This is consistent with human study which concluded that lean mass has stronger effect on BMD than fat mass in young women [14]. At young ages, growing bone is

actively acquiring bone mineral [15]. Healthy diet and sufficient physical activity are associated with leanness [16-17]. Conversely, obesity is highly related to poor diet and/or inactivity, thus, fat mass has not sufficient effect on bone density. Mechanical loading, together with other biochemistry factors, Figure 1 Densitometry measurement of mice after 10-wk HFD or NFD

a: BMD of the total body, femoral and lumbar region; b: BMD adjusted for body weight; c: BMD adjusted for fat mass; d: BMC of total body; e: BMC of lumber region; f: BMC of femora; g: Total bone area e; h: Spine area; i: Femoral area. BMD: bone mineral density; BMC: bone mineral content; HFD: high fat diet; NFD: normal fat diet; a P < 0.05; b P < 0.01, vs . NFD group cm 2

B M D (g /c m 2)

B M D (g /c m 2)

B M D (g /c m 2)

B M

C (g )

B M

C (g )

B M

C (g )

Figure 2 Biomechanical indices in femora of high fat diet

(HFD) and normal fat diet (NFD) mice

U l t i m a t e f o r c e (N )

S t i f f n e s s (N /m m )

W o r k t o f a i l u r e (J X 1000) S t r e n g t h /d e n s i t y

Figure 3 Measurements of bone metabolic markers HFD: high fat diet; NFD: normal fat diet a: Serum pyridinoline crosslinks (PYD) b: Serum osteocalcin P Y D (n m o l /L )

O s t e o c a l c i n

(n g /L )

B o n e a r e a (c m 2)

S p i n e a r e a (c m 2)

F e m o r a l a r e a (c m 2)

a: The strength of the bone b: The elastic deformation c: The energy bone can absorb before breaking d: The ratio of strength and bone density

Wang L, et al. Effects of a high-fat diet on bone development in growing mice

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promote the increase in BMC and bone size to compensate for the weight gain, which has been showed in our femoral measurements [18-21]. When evaluating the bone status in children and adolescence, it is recommended to use

size-corrected bone BMC [22-23]. We adjusted femur BMD, BMC for body weight or fat mass, and these measurements in HFD mice were lower than NFD mice, although the difference was not significant, which might due to the small sample size.

Several studies have proposed that extra weight from fat mass does not independently related to bone geometry. In overweight children and adolescents, proximal femur bone geometry is appropriately adapt to lean mass [24]. Dynamic force (muscle force), rather than static loads (body weight), causes a larger dynamic strain on bone and leads to the geometric

adaptation [25-26]. Another study also reported that in young women, lean tissue mass has a greater effect on bone density than fat mass per kilogram of tissue mass [14]. Taking the less effect of fat mass on bone geometry into consideration, this result indicated that the femoral response to higher mechanical loading from the excess fat mass might not be sufficient to compensate for the surplus load.

This is the first time to report that HFD since young age could reduce absolute spine BMC and bone area in female mice. It has been reported in human study that obese girl had smaller vertebral area than girls of healthy weight after adjustment for the body size [5]. Regarding present study, high saturated fat diet seemed to exert more detrimental effects on growing vertebral bone beyond the negative influence of adiposity. To date, information concerning how HFD from young age affect vertebral mineral accrual is sparse. Some earlier reports

suggest that obese children have limited ability to augment their spinal areal bone mineral density [27-28]. Yet, it is difficult to elucidate the true effect of fat mass on bone because of the complicated relationship [29]. One thing should be noted that the tempo of growth in bone size, mass and density is

region-specific (girls)[30]. In terms of this, unlike in adulthood, the effect of exposure to a risk factor during growth depends on the maturational level and growth rate of the region exposed, and before puberty, limbs grow more rapidly than axial bones. The lumber spine is mainly composed of trabecular bone and has the different sensitivity to mechanical stress from cortical bone. In this study, the loss of numbers of trabeculae was observed, indicating the damage of trabecular architecture. Therefore, vertebral bone might be more sensitive to the deleterious effect of HFD despite the beneficial bone accommodation to the concomitant obesity.

The discrepancy of high bone mass and increased risk of

fracture in obese children suggests that higher bone mass does not mean the higher bone quality [31]. As to bone quality, there is no current consensus about its definition. The authors prefer to the one proposed by Hernandez [32], that is, bone quality refers to the influence of factors that affect fracture but are not

accounted for by bone mass or quantity. To analyze bone quality, one approach is to calculate the ratio of strength to density for each inpidual specimen. Bones with higher ratio are more biomechanically efficient. We examined the bone

biomechanical properties of left femur and it turned out that the larger bone had a tendency to be stronger which is consistent with the study of obese male rats, but in present study, it did not attain statistical significance. When calculating the ratio of femur strength to femur bone density, higher ratio was seen in HFD mice, although the difference was not significant. This result could be explained as that HFD mouse have stronger weight-bearing bones because of greater load together with advanced maturity and bone ages, but this improvement of bone quality might be not enough relative to the weight gain because we did not see the significant difference of biomechanical properties between groups. In terms of

appendicular bone status, how long can the biomechanical improvement maintain, how the peak bone value will be

influenced if not changing the HFD, remain to be further studied. This reminds us another study with the results that prepubertal obese children had higher BMD, but a low BMD value was found after puberty [33].

In order to further understand the skeletal metabolism, we measured the specific bone metabolic markers, that is, bone resorption marker-pyridinoline (PYD) and bone formation marker-osteocalcin. We noted that both bone formation and resorption markers in HFD mice were lower than NFD mice, indicating a decreased bone turnover in HFD group. There are many factors influence the concentration of bone metabolic markers, such as age, pubertal stage, growth velocity, mineral accrual, hormonal regulation, nutritional status, etc [12]. In this study, nutritional status, prematurity and hormonal profiles are the disturbance to illustrate the impact of HFD on bone turnover, and there are fewer literatures to be referred about the bone turnover in young mice. However, human prospective study indicated that, bone markers increase rapidly during early puberty when growth velocity is highest and start to decrease after the growth spurt until reach values observed in adults during postpubertal period [34-35]. Bone markers are positively correlated with longitudinal growth, and the longer the pubertal increase of bone markers lasts, the higher pubertal growth increase, as well the higher bone mineral accrual [36]. According to this, our results indicate that the lower bone markers in HFD mice suggesting the lower growth velocity and subsequent less accumulation of bone mineral.

Our study has some limitations. We initially designed to use

Figure 4 Histological images of 14-wk-old high fat diet and normal fat diet mice (Hematoxylin-eosin staining,

×100) a: Normal fat diet group

b: High fat diet group

Wang L, et al. Effects of a high-fat diet on bone development in growing mice

ISSN 1673-8225 CN 21-1539/R CODEN: ZLKHAH

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both male and female mice and analyze influence of HFD on bone development in different genders. But more male mice died during the experiment, resulting in less number far from enough for statistical analysis. In present study, only data of female mice were analyzed. The small sample size and

relatively bigger standard deviation may influence the statistical analysis and diminish the significance. We did not measure serum endocrine factors, such as leptin, insulin, growth hormone or

estrogen, which have been already identified to affect bone status. Further studies are needed to unveil the potential mechanisms of HFD-related bone phenotype. It has been reported that in adult mice, HFD can inhibit the intestinal absorption of calcium and consequently deleteriously affects bone mineralization, and the adverse effect is more apparent in cancellous bone than in cortical bone [37-38]. In addition, adiposity of bone marrow may cause the imbalance of differentiation from stem cells to adipocytes or

osteoblasts [39]. As to the growing bone, the underline mechanisms might be more complicated. Although the results are not quite consistent with our experiment, a recent study also concluded that high fat diet intake during the growing period has deleterious effects on bone metabolism [40].

In conclusion, we studied the effect of HFD on bone growth. Our results showed femoral BMC, BMD and bone area increased in adaption to the excess body weight caused by HFD. However, these bone responses seem to be insufficient to compensate for the excess load regarding the body weight and fat mass. What is more conspicuous is the negative effect on lumbar spine growth. T o conclude, our preliminary data suggest that the vertebral bone is more sensitive to HFD-induced bone loss compared to the long bones in young, growing animals. Considering that childhood and adolescence are crucial periods to acquire nearly half of the peak bone mass, HFD in young age might be one reason for the

increasing prevalence of osteoporosis during adult and aging.

REFERENCES

[1]

Halpern A, Mancini MC, Magalh?es ME, et al. Metabolic

syndrome, dyslipidemia, hypertension and type 2 diabetes in youth: from diagnosis to treatment. Diabetol Metab Syndr. 2010;2:55.

[2] Bray GA, Popkin BM. Dietary fat intake does affect obesity! Am

J Clin Nutr. 1998;68(6):1157-1173.

[3] American Academy of Pediatrics. Committee on Nutrition.

Cholesterol in childhood. Pediatrics. 1998;101(1 Pt 1):141-147. [4] Power C, Lake JK, Cole TJ. Measurement and long-term health

risks of child and adolescent fatness. Int J Obes Relat Metab Disord. 1997;21(7):507-526.

[5] Goulding A, Jones IE, Taylor RW, et al. Bone mineral density

and body composition in boys with distal forearm fractures: a dual-energy x-ray absorptiometry study. J Pediatr. 2001; 139(4):509-515.

[6] Goulding A, Taylor RW, Jones IE, et al. Overweight and obese

children have low bone mass and area for their weight. Int J Obes Relat Metab Disord. 2000;24(5):627-632.

[7] Goulding A, Taylor RW, Jones IE, et al. Spinal overload: a

concern for obese children and adolescents? Osteoporos Int. 2002;13(10):835-840.

[8] Leonard MB, Shults J, Wilson BA, et al. Obesity during

childhood and adolescence augments bone mass and bone dimensions. Am J Clin Nutr. 2004;80(2):514-523.

[9] Hasano ?lu A, Bideci A, Cinaz P , et al. Bone mineral density in

childhood obesity. J Pediatr Endocrinol Metab. 2000;13(3): 307-311. [10] Bonjour JP , Theintz G, Buchs B, et al. Critical years and stages of

puberty for spinal and femoral bone mass accumulation during adolescence. J Clin Endocrinol Metab. 1991;73(3): 555-563. [11] Xie D, Cheng H, Hamrick M, et al. Glucose-dependent

insulinotropic polypeptide receptor knockout mice have altered bone turnover. Bone. 2005;37(6):759-769.

[12] Szulc P, Seeman E, Delmas PD. Biochemical measurements of

bone turnover in children and adolescents. Osteoporos Int. 2000;11(4):281-294.

[13] Botolin S, McCabe LR. Bone loss and increased bone adiposity

in spontaneous and pharmacologically induced diabetic mice. Endocrinology. 2007;148(1):198-205.

[14] Wang MC, Bachrach LK, Van Loan M, et al. The relative

contributions of lean tissue mass and fat mass to bone density in young women. Bone. 2005;37(4):474-481.

[15] Kyle UG, Morabia A, Schutz Y, et al. Sedentarism affects body

fat mass index and fat-free mass index in adults aged 18 to 98 years. Nutrition. 2004;20(3):255-260.

[16] Janz KF, Burns TL, Levy SM, et al. Everyday activity predicts

bone geometry in children: the iowa bone development study. Med Sci Sports Exerc. 2004;36(7):1124-1131.

[17] Bonjour JP, Carrie AL, Ferrari S, et al. Calcium-enriched foods

and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial. J Clin Invest. 1997;99(6):1287-1294.

[18] Roemmich JN, Clark PA, Mantzoros CS, et al. Relationship of

leptin to bone mineralization in children and adolescents. J Clin Endocrinol Metab. 2003;88(2):599-604.

[19] Klein KO, Larmore KA, de Lancey E, et al. Effect of obesity on

estradiol level, and its relationship to leptin, bone maturation, and bone mineral density in children. J Clin Endocrinol Metab. 1998;83(10):3469-3475.

[20] Hamrick MW. Perspective: leptin, bone mass, and the thrifty

phenotype. J Bone Miner Res. 2004;19:1607-1611.

[21] Rocher E, Chappard C, Jaffre C, et al. Bone mineral density in

prepubertal obese and control children: relation to body weight, lean mass, and fat mass. J Bone Miner Metab. 2008; 26(1):73-78.

[22] Prentice A, Parsons TJ, Cole TJ. Uncritical use of bone mineral

density in absorptiometry may lead to size-related artifacts in the identification of bone mineral determinants. Am J Clin Nutr. 1994;60(6):837-842.

[23] Whiting SJ. Obesity is not protective for bones in childhood and

adolescence. Nutr Rev. 2002;60(1):27-30.

[24] Petit MA, Beck TJ, Shults J, et al. Proximal femur bone

geometry is appropriately adapted to lean mass in overweight children and adolescents. Bone. 2005;36(3):568-576.

[25] Mosley JR, Lanyon LE. Strain rate as a controlling influence on

adaptive modeling in response to dynamic loading of the ulna in growing male rats. Bone. 1998;23(4):313-318.

[26] Mosley JR. Osteoporosis and bone functional adaptation:

mechanobiological regulation of bone architecture in growing and adult bone, a review. J Rehabil Res Dev. 2000; 37(2):189-199.

[27] McCormick DP, Ponder SW, Fawcett HD, et al. Spinal bone

mineral density in 335 normal and obese children and

adolescents: evidence for ethnic and sex differences. J Bone Miner Res. 1991;6(5):507-513.

[28] De Schepper J, Van den Broeck M, Jonckheer MH. Study of

lumbar spine bone mineral density in obese children. Acta Paediatr. 1995;84(3):313-315.

[29] Zhao LJ, Jiang H, Papasian CJ, et al. Correlation of obesity and

osteoporosis: effect of fat mass on the determination of osteoporosis. J Bone Miner Res. 2008;23(1):17-29.

[30] Bass S, Delmas PD, Pearce G, et al. The differing tempo of

growth in bone size, mass, and density in girls is region-specific. J Clin Invest. 1999;104(6):795-804.

[31] Turner CH. Biomechanics of bone: determinants of skeletal

fragility and bone quality. Osteoporos Int. 2002;13(2):97-104. [32] Hernandez CJ, Keaveny TM. A biomechanical perspective on

bone quality. Bone. 2006;39(6):1173-1181.

[33] Nagasaki K, Kikuchi T, Hiura M, et al. Obese Japanese children

have low bone mineral density after puberty. J Bone Miner Metab. 2004;22(4):376-381.

[34] Marowska J, Kobyli ńska M, Lukaszkiewicz J, et al. Pyridinium

crosslinks of collagen as a marker of bone resorption rates in children and adolescents: normal values and clinical application. Bone. 1996;19(6):669-677.

[35] Cadogan J, Blumsohn A, Barker ME, et al. A longitudinal study

of bone gain in pubertal girls: anthropometric and biochemical correlates. J Bone Miner Res. 1998;13(10):1602-1612.

[36] Bonjour JP, Theintz G, Buchs B, et al. Critical years and stages

of puberty for spinal and femoral bone mass accumulation during adolescence. J Clin Endocrinol Metab. 1991;73(3): 555-563.

[37] Atteh JO, Leeson S. Effects of dietary saturated or unsaturated

fatty acids and calcium levels on performance and mineral metabolism of broiler chicks. Poult Sci. 1984;63(11):2252-2260.

[38] Wohl GR, Loehrke L, Watkins BA, et al. Effects of high-fat diet

on mature bone mineral content, structure, and mechanical properties. Calcif Tissue Int. 1998;63(1):74-79.

[39] Lin TH, Yang RS, Tang CH, et al. PPARgamma inhibits

osteogenesis via the down-regulation of the expression of COX-2 and iNOS in rats. Bone. 2007;41(4):562-574.

[40] Lac G, Cavalie H, Ebal E, et al. Effects of a high fat diet on bone

of growing rats. Correlations between visceral fat, adiponectin and bone mass density. Lipids Health Dis. 2008;7:16.

Wang L, et al. Effects of a high-fat diet on bone development in growing mice

1326 P .O. Box 1200, Shenyang 110004 8e5bddb4376baf1ffd4fad26

www.CRTER .org 幼鼠骨骼发育中高脂饮食的影响*★○

王 娈1，阎胜利1，王 芳1，米庆胜○2, 3 (1青岛大学医学院附属医院内分泌科，山东省青岛市 266003；2亨利福特医院内科内分泌、糖

尿病、骨矿疾病组，美国底特律市 48202；3佐治亚州医学院生物工程和基因中心，美国佐治亚州 30912)

王娈★，女，1974年生，山东省青岛市人，

汉族，2000年青岛大学医学院毕业，硕士，

主治医师，主要从事骨质疏松及糖尿病方面

的研究。

通讯作者：阎胜利，教授，主任医师，青岛

大学医学院附属医院内分泌科，山东省青岛

市 266003

摘要

背景：高脂饮食能引起肥胖，成年人肥胖能

增加骨密度，对健康有一定的正面作用，而

高脂饮食对生长快速的儿童骨骼发育的影响

并不十分明确。

目的：观察高脂饮食对雌性幼鼠骨胳发育的

影响。

方法：取12只4周龄雌性CD1小鼠，分别

给予高脂饮食和正常饮食，喂养10周后用

双能X 射线骨密度仪扫描全身；用三点弯曲

实验检测骨生物力学特征；用酶联免疫分析

法检测血清中骨转换标志物；股骨组织切片

苏木精-伊红染色观察骨小梁变化和骨髓的

脂肪化程度。

结果与结论：高脂饮食组小鼠的体质量、体

脂含量均显著高于正常饮食组，但全身的骨

密度、骨矿物质含量、骨面积和肌肉组织含

量与正常饮食组无显著差异，但腰椎的骨密

度、骨矿物质含量和骨面积都显著低于正常

饮食组，而股骨的骨密度、骨矿物质含量和

骨面积都显著高于正常饮食组，经体质量或

体脂含量校正后虽然无显著统计学差异，但

高脂饮食组全身和股骨的骨密度、骨矿物质

含量和骨面积都呈现了低于正常饮食组的趋势；两组在骨生物力学特性方面的比较没有显著差异；高脂饮食组的血清骨转换标志物浓度较正常饮食组低；组织切片可见高脂饮食组的骨髓腔中有大量脂肪浸润和骨小梁宽度和面积减小。提示肥胖对生长旺盛阶段的幼鼠骨骼发育有不良影响，椎骨的骨矿物化程度下降，承重部位骨量的增加不能充分代偿体质量的增加。

关键词：饱和脂肪；骨密度；生物力学；骨发育；小鼠 doi:10.3969/j.issn.1673-8225.2011.07.041 中图分类号: R318 文献标识码: A 文章编号: 1673-8225(2011)07-01321-06 王娈，阎胜利，王芳，米庆胜.幼鼠骨骼发育中高脂饮食的影响[J].中国组织工程研究与临床康复，2011，15(7):1321-1326. [8e5bddb4376baf1ffd4fad26 8e5bddb4376baf1ffd4fad26] (Edited by Shi KH/Zhao LJ/Wang L)

致谢：衷心感谢美国佐治亚州医学院生物工程和基因中心的Byund Lee 博士和Ke-hong Ding 博士对本实验中骨密度测量 和骨生物力学检测给予的无私指导和帮助。 利益冲突：本课题不涉及任何厂家及相关雇主或其他经济组织直接或间接的经济或利益的赞助。 伦理批准：实验过程中对动物处置完全符合动物伦理学标准。试验经过美国佐治亚州医学院动物伦理委员会批准。 本文创新性： 提供证据：2010-10检索“Pubmed Home ”，检索关键词：high-fat diet ；bone ； development ，检索60篇文献；检索万方、维普和中国知网等，检索关键词：骨骼；高脂饮食，检索到42篇文献，但大多为研究骨骼肌细胞的内容。 创新点说明：本实验结合骨形态、机械力学特征、组织微结构变化和血清学检查，从不同层面反映了高脂饮食对幼鼠骨骼发育的不良影响，并首次提出椎骨对其负面作用可能更为敏感。 来自本文课题的更多信息-- 基金资助：国家自然科学基金(30671005)，项目名称“RAGE 基因高表达对小鼠破骨细胞的影响”。 作者贡献：实验由阎胜利和米庆胜设计并指导完成。实验实施为王娈、王芳完成，王娈收集资料、整理成文。阎胜利和米庆胜审校，阎胜利对文章负责。

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