High-fat diets affect energy and bone metabolism in growing rats

Background

High-fat diets are usually associated with greater weight (W) gain and body fat (BF). However, it is still unclear whether the type and amount of fat consumed influence BF. Additionally, dietary fat intake may also have consequences on skeletal health.

Objective

To evaluate in healthy growing rats the effects of high-fat diets and type of dietary fat intake (saturated or vegetable oils) on energy and bone metabolism.

Methods

At weaning, male Wistar rats (n?=?50) were fed either a control diet (C; fat?=?7% w/w) or a high-fat diet (20% w/w) containing either: soybean oil, corn oil (CO), linseed oil (LO), or beef tallow (BT) for 8?weeks. Zoometric parameters, BF, food intake and digestibility, and total and bone alkaline phosphatase (b-AP) were assessed. Total skeleton bone mineral density (BMD) and content (BMC), BMC/W, spine BMD, and bone volume (static-histomorphometry) were measured.

Results

Animals fed BT diet achieved lower W versus C. Rats fed high-fat vegetable oil diets showed similar effects on the zoometric parameters but differed in BF. BT showed the lowest lipid digestibility and BMC. In contrast, high vegetable oil diets produced no significant differences in BMC, BMC/W, BMD, spine BMD, and bone volume. Marked differences were observed for LO and BT groups in b-AP and CO and BT groups in bone volume.

Conclusion

BT diet rich in saturated fatty acids had decreased digestibility and adversely affected energy and bone metabolisms, in growing healthy male rats. There were no changes in zoometric and bone parameters among rats fed high vegetable oil diets.     

Excess body fat negatively affects bone mass in adolescents

ObjectiveThe aim of this study was to investigate the effects of excess body fat on bone mass in overweight, obese, and extremely obese adolescents.MethodsThis study included 377 adolescents of both sexes, ages 10 to 19 y. Weight, height, body mass index (BMI), bone age, bone mineral content (BMC), and bone mineral density (BMD) were obtained by dual-energy x-ray absorptiometry. The results were adjusted for chronological age and bone age. Comparisons according to nutritional classification were performed by analysis of variance, followed by Tukey test. Linear regression models were used to explain the variation in BMD and BMC in the L1–L4 lumbar spinal region, proximal femur, and whole body in relation to BMI, lean mass, fat mass (FM), and body fat percentage (BF%), considering P < 0.05.ResultsFor all nutritional groups, average bone age was higher than chronological age. In both sexes, weight and BMI values increased from eutrophic to extremely obese groups, except for BMD and BMC, which did not differ among male adolescents, and were smaller in extremely obese than in obese female adolescents (P < 0.01). Significant differences were observed for FM and BF% values among all nutritional groups (P < 0.01). Positive, moderate to strong correlations were detected between BMD and BMC for BMI, lean mass, and FM. A negative and moderate correlation was found between BMC and BF%, and between BMD and BF% at all bone sites analyzed in males and between BF% and spine and femur BMD, in females.ConclusionThe results reveal a negative effect of BF% on bone mass in males and indicate that the higher the BF% among overweight adolescents, the lower the BMD and BMC values.     

Diet,weight, cytokines and bone health in postmenopausal women

Objectives

To investigate diet and nutrition-related factors associated with bone loss in a group of postmenopausal (PM) women. Nutritional intake, inflammatory markers and body composition (weight, body mass index, fat/lean mass) were analysed for associations with bone mineral density (BMD).

Design

A cross sectional study examining correlations between BMD (Duel-energy X ray absorptiometry; (DXA) and dietary intake (3-day diaries), body composition and plasma bone and inflammatory markers: C-terminal telopeptide of type I collagen (CTX) and procollagen type I N propeptide (P1NP), C- reactive protein (CRP), interleukin 6 and 10 (IL-6, IL-10), tumour necrosis factor (TNF) and osteoprotegerin (OPG).

Setting

Community dwelling women from the Auckland, Hawke’s Bay and Manawatu regions in New Zealand.

Participants

142 healthy, PM women aged 50–70 years.

Results

OPG (per kilogram fat mass) was increased in women with osteoporosis (p<0.001) compared to groups classified with normal BMD and osteopenia. Protein, vitamin B12, zinc, potassium and dairy intake were all positively correlated with higher BMD while dairy and potassium intakes also inversely correlated with CTX. Body composition (weight, BMI and fat/lean mass) had strong positive associations with BMD. Multiple regression analysis showed body weight, potassium and dairy intake were predictors of increased BMD in PM women and explained 39% (r²=0.39, p< 0.003) of variance.

Conclusion

BMD was negatively correlated with OPG and positively with weight, dairy and potassium intake. This study highlights the importance of maintaining adequate body weight and emphasising dairy and potassium predominantly sourced from fruit/vegetables to reduce bone loss at midlife.     

Supplementation of ascorbic acid and alpha-tocopherol is useful to preventing bone loss linked to oxidative stress in elderly

Objective

To determine the effect of ascorbic acid and alpha-tocopherol on oxidative stress and bone mineral density (BMD) in elderly people.

Design

A double-blind, controlled clinical assay was carried out in a sample of 90 elderly subjects divided into three age-paired random groups with 30 subjects in each group. Group Tx0 received placebo, group Tx1 received 500 mg of ascorbic acid and 400 IU of alpha-tocopherol, whereas group Tx2 received 1,000 mg of ascorbic acid and 400 IU of alpha-tocopherol, for a 12-month period.

Measurements

We measured thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), superoxide dismutase (SOD), and glutation peroxidase (GPx); BMD was obtained on DXA of hip and spine before and after the 12-month treatment period with supplementation of vitamins C and E.

Results

We found a positive correlation between hip-BMD and SOD (r = 0.298, p <0.05) and GPx (r = 0.214, p <0.05). Also, a significantly lower decrease of LPO (p <0.05) was observed as linked with hip bone loss in the Tx2 group than in the Tx0 group.

Conclusions

Our findings suggest that that administration of 1,000 mg of ascorbic acid together with 400 IU of alpha-tocopherol could be useful in preventing or aiding in the treatment of age-related osteoporosis.     

Low dietary calcium and obesity: a comparative study in genetically obese and normal rats during early growth

Purpose

A low calcium intake (LCaI) may predispose to obesity, and excessive fat mass may be detrimental to bone. The impact of Ca inadequacy would be greater in subjects predisposed to obesity. LCaI effect on obesity development during the rapid growth period was compared in two strains of rats: spontaneously obese IIMb/β (O) and Wistar (W). Pregnant rats were fed 0.5 % (N) or 0.2 % (L) of Ca (OLCa, ONCa, WLCa and WNCa). Male pups were fed the maternal diet until day 60.

Methods

Body composition, lipid profile, glucose homeostasis, 25 hydroxyvitamin D, Ca-phosphorus, and bone metabolism were evaluated.

Results

BW and body fat were higher, whereas body protein was lower in OLCa versus ONCa (p < 0.05). OLCa presented the highest body fat, glucose, non-HDL and total cholesterol, TGL, insulin levels, and HOMA-IR, liver weight, and adipose perigonadal plus retroperitoneal pads (p < 0.05). WLCa did not exhibit an increase BW and only showed a slight change in body composition with minor biochemical alterations compared to WNCa (p < 0.05). Osteocalcin, CTX, and proximal tibia and lumbar spine BMDs were lower in O than in W rats fed the same Ca diet (p < 0.05). Body ash and Ca content, and total skeleton BMC/BW were lower in OLCa and WLCa versus their corresponding NCa groups (p < 0.05).

Conclusion

The negative effect of a low Ca diet on fat mass accumulation and lipid profile may be more evident in rats predisposed to obesity. Nevertheless, low CaI interferes with the normal glucose homeostasis leading to an increase in insulin resistance. Low CaI during early growth may be an obesogenic factor that may persist into adult life and may account for the development of obesity and some of its co-morbidities.     

Long-term maintenance of weight loss after lifestyle intervention in frail, obese older adults

Objectives

To determine if long-term weight loss with associated improvement in physical and metabolic health can be maintained after lifestyle intervention in frail, obese older adults.

Design

Thirty-month follow-up pilot study of a 1-year lifestyle intervention trial.

Setting

Community.

Participants

Sixteen frail, obese (body mass index=36±2 kg/m2) older (71±1 yr.) adults.

Measurements

Body weight and composition, physical function, markers of the metabolic syndrome, glucose and insulin response to an oral glucose tolerance test, bone mineral density (BMD), liver and renal function tests, and food diaries.

Results

At 30-month follow-up, weight (101.5±3.8 vs. 94.5±3.9 kg) and BMI (36.0 ±1.7 vs. 33.5±1.7 kg/m²) remained significantly below baseline (all p<0.05). No significant change in fat-free mass (56.7±2.1 vs. 56.9±2.2 kg) or appendicular lean mass (24.1±1.0 vs. 24.1±1.1kg, all p>0.05) occurred between 12 months (end of trial) and 30 months. Improvements in the physical performance test (PPT 27±0.7 vs. 30.2±0.6), insulin sensitivity (4.1±0.8 vs. 3.0±0.6), and insulin area under the curve (12484±2042 vs. 9270±1139 min.mg/dl) remained at 30 months compared to baseline (all p<0.05). Waist circumference (116±3 vs. 109±3 cm) and systolic blood pressure (134±6 vs. 123±5 mm HG) remained decreased at 30 months compared to baseline (all p<0.05). Whole body and lumbar spine BMD did not change; however, total hip BMD progressively decreased at 30 months compared to baseline (0.985±.026 vs. 0.941±.024 g/cm²; p<0.05). There were no adverse effects on liver or renal function. Food frequency questionnaire data showed lower overall caloric intake (?619±157 kcal/day) at 30 months compared to baseline (p<0.05).

Conclusion

These findings suggest that long-term maintenance of clinically important weight loss is possible in frail, obese older adults. Weight maintenance appears to be achieved through continued caloric restriction. Larger, long-term studies are needed to follow up on these findings and investigate mechanisms and behaviors underlying maintenance of weight loss and physical function.     

Association of protein intake with bone mineral density and bone mineral content among elderly women: The OSTPRE fracture prevention study

Abstract

It has been hypothesized that high protein intakes are associated with lower bone mineral content (BMC). Previous studies yield conflicting results and thus far no studies have undertaken the interaction of body mass index (BMI) and physical activity with protein intakes in relation to BMC and bone mineral density (BMD).

Objective

To evaluate the associations of dietary total protein (TP), animal protein (AP) and plant protein (PP) intakes with BMC and BMD and their changes. We tested also the interactions of protein intake with, obesity (BMI ≤30 vs. >30 kg/m2) and physical activity level (passive vs. active).

Design/ Setting

Prospective cohort study (Osteoporosis Risk-Factor and Fracture-Prevention Study).

Participants/measures

At the baseline, 554 women aged 65-72 years filled out a 3-day food record and a questionnaire covering data on lifestyle, physical activity, diseases, and medications. Intervention group received calcium 1000 mg/d and cholecalciferol 800 IU for 3 years. Control group received neither supplementation nor placebo. Bone density was measured at baseline and year 3, using dual energy x-ray absorptiometry. Multivariable regression analyses were conducted to examine the associations between protein intake and BMD and BMC.

Results

In cross-sectional analyses energy-adjusted TP (P≤0·029) and AP (P≤0·045) but not PP (g/d) were negatively associated with femoral neck (FN) BMD and BMC. Women with TP≥1·2 g/kg/body weight (BW) (Ptrend≤0·009) had lower FN, lumbar spine (LS) and total BMD and BMC. In follow-up analysis, TP (g/kg/BW) was inversely associated with LS BMD and LS BMC. The detrimental associations were stronger in women with BMI<30 kg/m². In active women, TP (g/kg/BW) was positively associated with LS BMD and FN BMC changes.

Conclusions

This study suggests detrimental associations between protein intake and bone health. However, these negative associations maybe counteracted by BMI>30 kg/m2 and physical activity.

     

Impact of body mass index on the relationship between muscle quality and physical function in older women

Objectives

To investigate the impact of body mass index (BMI) (normal weight, overweight, obese) on the relationship between muscle quality (MQ) and physical function in community-dwelling older women.

Design

Cross-sectional study.

Setting

University research laboratory.

Participants

Community-dwelling older women (n = 94, 73.6 ± 5.4 y) stratified by BMI (normal weight: 20.0–24.9 kg/m²; overweight: 25.0–29.9 kg/m²; obese: ≥ 30.0 kg/m²).

Measurements

Body mass index using height and weight, leg extension power via the Nottingham power rig, body composition using dual-energy X-ray absorptiometry, and physical function (6-minute walk, 8-foot up-and-go, 30-second chair stand). Muscle quality was defined as leg power (watts) normalized for lower-body mineral-free lean mass (kg).

Results

Following adjustments for covariates, muscle quality was significantly higher in women of normal BMI compared to overweight (10.0 ± 0.4 vs 8.7 ± 0.4 watts/kg, p = 0.03). Muscle quality was a significant predictor of performance on the 6-minute walk and 8-foot up-and-go in normal and overweight women (all p < 0.05) and performance on the 30-second chair stand in normal and obese women (both p < 0.05). Body mass index did not significantly impact the association between MQ and physical function (all p > 0.05).

Conclusions

Muscle quality varies by BMI, yet the relationship to physical function is not significantly different across BMI groups. The results imply that interventions that increase MQ in older women may improve physical function, regardless of BMI.     

大鼠骨矿物质含量与组织中钙水平的相关性研究

用ＳＤ１０００型单光子骨矿物测定仪研究了９８只１５周龄Ｗｉｓｔａｒ大鼠的股骨矿物质含量（ＢＭＣ）和骨密度（ＢＭＤ，ＢＭＣ／ＢＷ）与组织和血中钙含量的相关性。结果显示：雌、雄动物的身长、体重、骨宽度（ＢＷ）、ＢＭＣ、ＢＭＣ／体重、ＢＭＤ／体重及ＢＭＤ／身长均有显著性差异，活体ＢＭＤ与动物的钙总摄入量、身长、体重、及钙存留率显著相关（Ｐ＜０．０５）；ＢＭＣ与钙总摄入量、身长、体重、性别和肝脏钙含量显著相关（Ｐ＜０．０５）。多元回归分析表明：动物身长、体重、钙总摄入量和心脏钙含量与活体ＢＭＤ呈线性关系，动物身长和血浆钙含量与离体ＢＭＤ呈线性关系。活体测量结果ＢＭＣ、ＢＭＤ由于其与动物的生长发育、钙存留率及肌肉和血浆钙含量具有相关和直线关系，且简便易行、不需要处死动物，因而认为可以反映动物体内钙营养状况和骨质积累情况。     

Tea consumption is associated with increased bone strength in middle-aged and elderly Chinese women

Objectives

Previous studies found that tea consumption was related to a reduction in the risks of some chronic diseases, but limited data are available on bone health. This study aimed to examine the associations of tea consumption with hip bone strength in Chinese women.

Design

Cross-sectional study.

Setting

The participants were from the ongoing Guangzhou Nutrition and Health Study. This was a cohort study started in 2008. The examination data conducted between June 2010 and December 2013 were used.

Participants

A total of 1,495 Chinese women aged more than 40 years were included.

Measurements

Tea consumption, sociodemographic information and lifestyle habits were collected by a face-to-face questionnaire. Hip bone mineral density (BMD) and geometric parameters, i.e. cross-sectional area (CSA), section modulus (Z) and buckling ratio (BR), were generated by dual-energy X-ray absorptiometry. The associations of tea consumption with bone phenotypes were detected by analysis of covariance and multiple linear regression models after adjusting for age, body mass index, years since menopause, physical activity, dietary-protein intake, dietary-calcium intake, calcium tablet intake, drinking status and smoking status.

Results

Tea drinkers (n = 732) had approximately 1.9% higher BMD (p < 0.05) and 3.6% lower BR (p < 0.05) than non-tea drinkers (n = 763). The dose-response relationships of BMD, BR or CSA with total tea consumption were identified (p-trend < 0.05). Tea drinking was found to be a significant and independent predictor of BMD (β = 0.068, p < 0.05) or BR (β = -0.079, p < 0.05).

Conclusion

Tea consumption was associated with increased bone strength in middle-aged and elderly Chinese women.

     

Sodium and calcium intakes and bone mass in rats revisited

OBJECTIVE: High sodium intake accompanied by insufficient dietary calcium may have detrimental effects on bone mass. Our study evaluated the effects of increased sodium and decreased calcium intakes on bone mineral density (BMD) and bone mineral content (BMC) in rats. METHODS: Four-month-old female Wistar rats were given deionized water or 1.8% solution of sodium chloride in deionized water and fed normal (1.2%) or marginal (0.33%) calcium in the diet for 2 mo. At the end of the experiment, BMD and BMC of the whole body and urinary sodium and calcium excretion were evaluated. All rats were killed and right femurs were removed to assess dry and ash weights. Two-way analysis of variance was used to evaluate effect of salt intake and effect of dietary calcium on these parameters. RESULTS: Salt-loaded animals had greater water consumption during the entire 2-mo period and significantly lower body weight from week 5 of the experiment. High salt intake increased urine volume and urinary excretion of sodium and calcium. Urinary calcium was about five times higher in salt-loaded animals than in rats on deionized water irrespective of dietary calcium content. Calcium in diet itself had no significant effect on these parameters. High salt intake slightly, but not significantly, decreased BMD, BMC, and femur weights. Lower calcium in diet significantly decreased BMD, and its effect on femur ash weight almost reached a level of significance. CONCLUSION: We confirmed the benefit of adequate calcium intake to BMD. Under our experimental condition, high salt intake in rats for 2 mo had no statistically significant effect on femur weights, BMD, or BMC even with marginal calcium in the diet.     

Decreases in bone mineral content by dietary all-trans retinoic acid precede decreases in bone mineral density in a weanling rat model of cigarette smoke-induced lung injuries

Research has indicated that excessive vitamin A can have deleterious impacts on bone. Retinoic acid (RA), the most active metabolite of vitamin A, has been tested in clinical trials for treatment of lung cancer and emphysema. These trials are not measuring Bone Mineral Content (BMC) or Bone Mineral Density (BMD). In this study, we used an animal model to determine potential deleterious effects of all-trans RA on bone mass when used as a means to protect against or treat cigarette smoke-induced lung injuries, and also to evaluate BMC as a potential early indicator of osteoporosis risk. Twenty-four male weanling rats were fed either a control diet or a RA-supplemented diet. Half of each group was exposed to 40 cigarettes per day, 5 days per week, for 4 weeks. BMC and BMD were measured at weeks 2 and 4. RA supplementation in all groups significantly decreased (p < 0.05) only BMC at week 2 and both BMC and BMD (both p < 0.05) at week 4. The same results were observed when BMC was expressed relative to body weight. These data suggest that caution should be used when RA is used to treat smoke-related lung injuries.     

小剂量17β-雌二醇对预防卵巢切除大鼠骨丢失的研究

为观察生理剂量的１７β－雌二醇（Ｅ２）对卵巢切除大鼠骨代谢、骨密度和骨力学特性的影响。将大鼠分为假手术组（Ａ）、去卵巢组（Ｂ）和去卵巢并给雌二醇组（Ｃ）。给Ｅ２９周后同时处死各组大鼠。结果Ｂ组大鼠血清碱性磷酸酶（ＡＬＰ）和骨钙素（ＯＣ）水平明显上升,右股骨近端１／３及第三腰椎骨密度（ＢＭＤ）明显低于对照组,雌二醇可逆转上述情况。Ｂ组骨力学参数明显低于对照组,而Ｃ组力学参数未见好转。结论认为生理剂量Ｅ２可抑制骨吸收和骨形成并增强骨量,但骨强度未见明显改善。     

Low levels of dietary arachidonic and docosahexaenoic acids improve bone mass in neonatal piglets, but higher levels provide no benefit

In piglets, feeding arachidonic acid (AA) and docosahexaenoic acid (DHA) in a 5:1 ratio leads to elevated bone mass, but the optimal total quantity requires clarification. We studied bone mass and modeling of piglets that were randomized to receive 1 of 4 formulas for 15 d: control formula or the same formula with various levels of AA:DHA (0.5:0.1 g, 1.0:0.2 g or 2.0:0.4 g AA:DHA/100 g of fat). Measurements included: bone area (BA), mineral content (BMC), and density (BMD) of whole body, lumbar spine, and excised femurs; biomarkers of bone modeling were plasma osteocalcin and urinary cross-linked N-telopeptides of type 1 collagen (NTx), tibial ex vivo release of prostaglandin E(2) (PGE(2)), plasma insulin-like growth factor-1 (IGF-1), and tissue fatty acids. Main effects were identified using ANOVA and post hoc Bonferroni t tests. In supplemented piglets, relations among liver fatty acid proportions and bone mass were assessed using Pearson correlations. Whole body (P = 0.028) and lumbar spine (P = 0.043) BMD were higher in the group supplemented with 0.5:0.1 g AA:DHA/100 g of fat than in controls. Tissue AA and DHA increased in proportion to diet levels. Liver eicosapentaenoic acid (EPA) correlated positively (r > or = 0.38, P < or = 0.05) with whole body and femur BMC and BMD and lumbar spine BMC. Liver AA:EPA ratio correlated negatively (r > or = -0.039, P < or = 0.05) with whole body, femur, and lumbar spine BMC plus whole body and femur BMD. Dietary 1.0:0.2 g AA:DHA/100 g reduced NTx relative to 2.0:0.4 g AA:DHA/100 g of fat (P = 0.039). The diets did not affect the other biochemical variables measured. Low levels of dietary AA:DHA (0.5:0.1 g/100 g of fat) elevate bone mass, but higher amounts are not beneficial.     

Increased gain in bone mineral content of preterm infants fed an isocaloric, protein-, and mineral-enriched postdischarge formula

Purpose

Preterm infants are at risk for suboptimal bone mineralization. Postnatal bone formation requires optimal nutritional composition. This study evaluated the effect of isocaloric, protein-, and mineral-enriched postdischarge formula (PDF), standard term formula (TF), and human milk (HM) on gain in bone mineral content (BMC) of preterm infants between term age (40 weeks postmenstrual age) and 6 months corrected age (CA).

Methods

Between term age and 6 months CA, 93 preterm infants were randomized to be fed PDF (n = 52) or TF (n = 41) and 46 preterm infants were fed HM. Weight (g) and length (cm) were measured at birth, term age, and 6 months CA. BMC (g) was measured by whole-body dual-energy x-ray absorptiometry at term age and 6 months CA.

Results

Gain in BMC (expressed as median with interquartile range) between term age and 6 months CA was higher in PDF-fed infants (102.3 (32.4) g) compared to TF- and HM-fed infants (91.6 (24.5) and 84.5 (33.3) g, respectively), adjusted for gender, gestational age, birthweight, and gain in weight and length.

Conclusion

Between term age and 6 months CA, isocaloric PDF enhances gain in BMC of preterm infants, independent of gain in weight and length. We speculate that higher gain in BMC during infancy may improve adult bone mass in preterm infants.     

Serum level of under-carboxylated osteocalcin and bone mineral density in early menopausal Norwegian women

Purpose

Serum level of under-carboxylated osteocalcin (ucOC) is considered a sensitive measure of vitamin K status, and ucOC levels are associated with bone mineral density (BMD) and fracture risk in elderly persons. The aim of this study was to assess the relationship between ucOC and BMD in early menopausal women.

Methods

The data reported here come from the enrolment in a double-blinded placebo-controlled randomized trial comprising 334 healthy Norwegian women between 50 and 60 years, 1–5 years after menopause, not using warfarin or medication known to affect bone metabolism. Total hip, femoral neck, lumbar spine, and total body BMD and serum level of ucOC and total osteocalcin were measured, and information of lifestyle was collected through questionnaires. The association between ucOC and BMD at all measurement sites was assessed by multiple regression analyses adjusting for possible confounding variables.

Results

The absolute serum level of ucOC was significantly and negatively associated with BMD at all measurements sites, both in univariate analyses (p < 0.01) and in multivariate analyses adjusting for years since menopause, smoking status and weight (p < 0.01). However, serum ucOC, expressed as percentage of the total osteocalcin level, was not associated with BMD at any site.

Conclusions

Achievement of adequate vitamin K nutritional intake is important, but ucOC expressed as percentage of total osteocalcin levels as reflection of vitamin K status does not seem to play a central role in determining BMD levels in early menopausal women.     

Maternal Vitamin D Status and Gestational Weight Gain as Correlates of Neonatal Bone Mass in Healthy Term Breastfed Young Infants from Montreal,Canada

The implications of maternal gestational weight gain (GWG) and vitamin D status to neonatal bone health are unclear. We tested whether maternal 25-hydroxyvitamin D (25(OH)D) and GWG relate to neonatal bone mineral content (BMC) and bone mineral density (BMD). Healthy term appropriate for gestational age breastfed neonates (n = 142) and their mothers were recruited 24–36 h after delivery and followed at 1.0 ± 0.5 month. At birth, obstetric data were collected and newborn serum 25(OH)D was measured. At 1 month, neonatal whole-body (WB) BMC, WB BMC relative to body weight (WB BMC/kg), lumbar spine BMC and BMD, maternal and neonatal 25(OH)D concentrations, and anthropometry were measured. Infant BMC and BMD between maternal 25(OH)D (<50, ≥50 nmol/L) and GWG (insufficient, adequate, and excessive) categories were compared. Maternal 25(OH)D was not related to infant whole-body BMC, BMC/kg, lumbar spine BMC, and BMD. Infants in the excessive maternal GWG category had greater (p = 0.0003) whole-body BMC and BMC/kg and lumbar spine BMC and BMD than inadequate GWG, and greater (p = 0.0063) whole-body BMC/kg and lumbar spine BMC and BMD than adequate GWG. These results suggest that maternal GWG, but not vitamin D status, modestly relates to bone mass in neonates.     

Vitamin D status in young Swedish women with anorexia nervosa during intensive weight gain therapy

Purpose

Anorexia nervosa (AN) is associated with reduced bone mass and an increased fracture risk. The aim was to evaluate the vitamin D status and the association with body mass index (BMI), fat mass and bone mineral density (BMD) in patients with severe AN during a prospective intervention study of intensive nutrition therapy.

Methods

This study comprised 25 Swedish female AN patients (20.1 ± 2.3 years), who were treated as inpatients for 12 weeks with a high-energy diet. Serum 25-hydroxyvitamin D (25(OH)D), calcium, phosphate and parathyroid hormone (PTH) were measured. BMD and body composition were assessed by dual-energy X-ray absorptiometry at study start and after 12 weeks.

Results

Twenty-two patients completed the study. The mean weight gain was 9.9 kg and BMI (mean ± SD) increased from 15.5 ± 0.9 to 19.0 ± 0.9 kg/m², P < 0.0001. Fat mass increased from median 12 to 27 %. The median serum 25(OH)D level was 84 nmol/L at baseline, which decreased to 76 nmol/L, P < 0.05. PTH increased from median 21.9 to 30.0 ng/L, P < 0.0001. BMC increased during the study period, P < 0.001.

Conclusions

Serum 25(OH)D levels were adequate both at study start and completion, however, nominally decreased after the 12-week nutritional intervention. PTH increased subsequently, which coincide with the decreased 25(OH)D levels. The reduction in 25(OH)D could be due to an increased storage of vitamin D related to the increase in fat mass since vitamin D is sequestered in adipose tissue.

     

Longitudinal and age trends of metabolic syndrome and its risk factors: The Family Heart Study

Background

Sub-optimally nourished rats show reduced growth, biochemical and physiological changes. However, no one has assessed metabolic rate adaptations in rats subjected to chronic suboptimal nutrition (CSN). In this study energy expenditure (EE; kcal/100 g body weight) and physical activity (PA; oscillations in weight/min/kg body weight) were assessed in rats subjected to three levels of CSN.

Results

Body weight gain was diminished (76.7 ± 12.0 and 61.6 ± 11.0 g) in rats fed 70 and 60% of the ad-libitum fed controls which gained more weight (148.5 ± 32.3 g). The rats fed 80% gained weight similarly to controls (136.3 ± 10.5 g). Percent Fat-free body mass was reduced (143.8 ± 8.7 and 142.0 ± 7.6 g) in rats fed 70 and 60% of ad-libitum, but not in those fed 80% (200.8 ± 17.5 g) as compared with controls (201.6 ± 33.4 g). Body fat (g) decreased in rats fed 80% (19.7 ± 5.3), 70% (15.3 ± 3.5) and 60% (9.6 ± 2.7) of ad-libitum in comparison to controls (26.0 ± 6.7). EE and PA were also altered by CSN. The control rats increased their EE and PA during the dark periods by 1.4 ± 0.8 and 1.7 ± 1.1 respectively, as compared with light the period; whereas CSN rats fed 80 and 70% of ad-libitum energy intake had reduced EE and PA during the dark periods as compared with the light period EE(7.5 ± 1.4 and 7.8 ± 0.6 vs. 9.0 ± 1.2 and 9.7 ± 0.8; p < 0.05, respectively), PA(3.1 ± 0.8 and 1.6 ± 0.4 vs. 4.1 ± 0.9 and 2.4 ± 0.4; p < 0.05) and RQ (0.87 ± 0.04 and 0.85 ± 0.5; vs. 0.95 ± 0.03 and 0.91 ± 0.05 p < 0.05). In contrast, both light (7.1 ± 1.4) and dark period (6.2 ± 1.0) EE and PA (3.4 ± 0.9 and 2.5 ± 0.5 respectively) were reduced in rats fed 60% of ad-libitum energy intake.

Conclusion

CSN rats adapt to mild energy restriction by reducing body fat, EE and PA mainly during the dark period while growth proceeds and lean body mass is preserved. At higher levels of energy restrictions there is decreased growth, body fat and lean mass. Moreover EE and PA are also reduced during both light and dark periods.     

(n-3) fatty acids reduce the release of prostaglandin E2 from bone but do not affect bone mass in obese (fa/fa) and lean Zucker rats

Childhood obesity is prevalent and linked to the development of Type 2 diabetes mellitus (DM) and poor bone health. Some PUFA enhance bone mass and thus may improve bone health in obese children. The study objective was to determine the effects of dietary (n-6) compared with (n-3) essential PUFA and long-chain PUFA (LCPUFA) on bone in an obese and insulin-resistant state. Male fa/fa (n = 48) and lean Zucker rats (n = 48) were fed diets containing safflower oil [SO, high (n-6) PUFA], flaxseed oil [FXO, high (n-3) PUFA], or menhaden oil [MO, high (n-3) LCPUFA] for 9 wk. Measurements included the following: femur bone area (BA), mineral content (BMC), density (BMD), morphometry and ex vivo release of prostaglandin E(2) (PGE(2)); plasma osteocalcin and C-terminal telopeptides of type I collagen. Differences among groups were detected using 2-way ANOVA. Genotype effects in the fa/fa rats included lower femoral weight, length, BA, and BMC, as well as femoral head and proximal epiphysis widths compared with the lean rats, but BMD was not affected. Femur BA, BMC, and BMD did not differ among the dietary groups, but diaphysis width was elevated in the MO group and PGE(2) release was reduced by the FXO and MO diets. No genotype x diet interactions were observed. These data indicate that the fa/fa Zucker rat is at risk for low bone mass and that dietary (n-3) FA effectively reduce PGE(2) release. Whether reduced PGE(2) will support optimal peak bone mass during childhood and conserve bone mass with aging warrants investigation.