The association between fat and lean mass and bone mineral density: the Healthy Twin Study

A cross-sectional study to examine the correlation between serum TSH levels and the osteoporosis of the lumbar spine in healthy women with normal thyroid function

We examined the association between serum TSH levels and osteoporosis of the lumbar spine in 756 Korean women aged 65 years or older with normal thyroid function. Low-normal serum TSH levels might be a potential risk factor for the osteoporosis in non-obese elderly women.

INTRODUCTION

We aimed to examine the association between serum thyroid-stimulating hormone (TSH) levels and osteoporosis of the lumbar spine in healthy elderly Korean women with normal thyroid function.

METHODS

In this cross-sectional study, we evaluated the correlations between serum TSH levels and the osteoporosis of the lumbar spine depending on the body mass index (BMI) in a total of 756 women aged 65 years or older who underwent bone mineral density (BMD) measurement and thyroid function test in a routine health screening examination at our medical institution.

RESULTS

After the adjustment of the age and BMI, there was a significant positive correlation between serum TSH level within normal range and the BMD of the lumbar spine (r = 0.165, P < 0.001). In the non-obese elderly women, multivariate-adjusted odds ratios (ORs) for the osteoporosis of the lumbar spine were significantly higher in the 1st and 2nd quartiles of serum TSH levels as compared with their 4th quartile (OR 2.169, 95% CI 1.128-4.171; and OR 2.122, 95% CI 1.123-4.007, respectively). In these women, there were dose-dependent inverse correlations between quartiles of serum TSH levels and the osteoporosis of the lumbar spine (P for trend, 0.008). In the obese women, however, there were no such correlations.

CONCLUSIONS

In conclusion, our results suggest that low-normal serum TSH levels might be a potential risk factor for the osteoporosis of the lumbar spine in non-obese elderly women. But further prospective, large-scale, randomized controlled studies are warranted to establish our results.

A fruit, milk and whole grain dietary pattern is positively associated with bone mineral density in Korean healthy adults

BACKGROUND/OBJECTIVES

Osteoporosis is a major health problem that will grow in burden with ageing of the global population. Modifiable risk factors for osteoporosis, including diet, have significant implications for disease prevention. We examined associations between dietary patterns and bone mineral density (BMD) in a Korean adult population.

SUBJECTS/METHODS

In total, 1828 individuals from the Healthy Twin Cohort were included as subjects. Information on general characteristics, lifestyles and health status was obtained through a health examination, and BMD was assessed using DEXA. Dietary intake was assessed using a 3-day food record, and dietary patterns were examined by factor analysis. Associations between dietary patterns and BMD were examined using mixed linear regression, adjusting for family and twin structure as well as other potential risk factors for bone health.

RESULTS

Four dietary patterns were identified (Rice and kimchi; eggs, meat and flour; Fruit, milk and whole grains; and Fast food and soda). The 'Fruit, milk and whole grains' pattern was associated with a reduced risk of having low BMD in men (odds ratio (OR)=0.38; 95% confidence interval (CI)=0.22-0.67) and women (OR=0.45; 95% CI=0.28-0.72) and was positively associated with BMD at multiple sites. The 'rice and kimchi' pattern had a positive association with only whole-arm BMD in men and women.

CONCLUSIONS

Our results suggest that a dietary pattern with high intake of dairy products, fruits and whole grains may contribute positively to bone health in a Korean adult population, and dietary pattern-based strategies could have potential in promoting bone health.

Assessment of lean (muscle) mass and its distribution by dual energy X-ray absorptiometry in healthy Indian females

SUMMARY

Mean appendicular lean mass increased from the second decade to reach maximum in the fourth decade in Indian women. Post-menopausal females with LMM were significantly older, leaner, and had lower bone mineral density (BMD). Lean mass and ASMI were negatively correlated with age and positively with BMI and BMD at all sites.

INTRODUCTION

Sarcopenia is defined by low muscle mass (LMM), strength, and performance. Lean mass can be precisely measured by dual-energy X-ray absorptiometry (DXA). There is no uniform definition of LMM. We undertook this study to prepare percentile charts for lean mass, which serves as a surrogate for muscle mass, in apparently healthy Indian females and correlate it with anthropometric and bone mineral density (BMD) parameters.

METHODS

This cross-sectional study included 1,045 apparently healthy females who participated in a general health examination. They were evaluated for anthropometry, lean mass, and BMD. LMM was defined by appendicular skeletal muscle mass index (ASMI) of <5.5 kg/m(2) (European cutoff) and <5.11 kg/m(2) (<20th centile of this study population cutoff). The study subjects were categorized as pre-menopausal (<50 years) or post-menopausal (>50 years).

RESULTS

Mean age and BMI were 44.0 ± 17.1 years and 25.0 ± 5.2 kg/m(2), respectively. Mean total and appendicular lean mass (arm and leg) increased from the second decade to reach maximum in the fourth decade, and then declined. LMM was present in 341 (32.6%) and 157 (15%), respectively, with European and study-based cutoff (ASMI 5.11 kg/m(2)). Twenty percent of post-menopausal females had LMM. Post-menopausal females with LMM were significantly older, leaner, and had lower BMD. Lean mass and ASMI were negatively correlated with age and positively with BMI and BMD at all sites.

CONCLUSIONS

Peak muscle mass among Indian females is achieved in the fourth decade, and they have lower total and regional lean mass than other ethnic groups.

Lean mass as a predictor of bone density and microarchitecture in adult obese individuals with metabolic syndrome

The effects of obesity and metabolic syndrome (MS) on bone health are controversial. Furthermore, the relationship between body composition and bone quality has not yet been determined in this context. The aim of this study was to investigate the correlations between body composition and bone mineral density (BMD) and bone microstructure in obese individuals with MS. This cross-sectional study assessed 50 obese individuals with MS with respect to their body composition and BMD, both assessed using dual X-ray absorptiometry, and bone microarchitecture, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal tibia and radius. Several HR-pQCT measurements exhibited statistically significant correlations with lean mass. Lean mass was positively correlated with parameters of better bone quality (r: 0.316-0.470) and negatively correlated with parameters of greater bone fragility (r: -0.460 to -0.310). Positive correlations were also observed between lean mass and BMD of the total femur and radius 33%. Fat mass was not significantly correlated with BMD or any HR-pQCT measurements. Our data suggest that lean mass might be a predictor of bone health in obese individuals with MS.

Importance of fat mass and lean mass on bone health in men: the Fourth Korean National Health and Nutrition Examination Survey (KNHANES IV)

This study was aimed to evaluate the association between body composition and bone health. High lean mass and low fat mass have protective effects on bone health in men representative of the national population.

INTRODUCTION

The aim of this study was to evaluate the association between body composition (fat mass and lean mass) and bone health in men.

METHODS

Totally, 3,945 men (age ≥ 20 years) from the fourth Korean National Health and Nutrition Examination Survey of 2008-2009 (KNHANES IV) were included in this study. Body composition and bone mineral densities (BMDs) were measured using dual energy X-ray absorptiometry. Osteopenia or osteoporosis was identified on the basis of the World Health Organization T-score criteria.

RESULTS

Multiple linear regression analyses showed that BMDs of the whole body, femoral neck, and lumbar spine were positively associated with lean mass and negatively associated with fat mass, after controlling for body weight and other potential confounders. Subjects with more fat mass or less lean mass, categorized according to quartiles of fat mass and lean mass, had higher odds of having osteopenia or osteoporosis, as shown by multivariable logistic regression (P for trend <0.001).

CONCLUSIONS

High lean mass and low fat mass have protective effects on bone health in a population of Korean adult men. Fat mass appears to exert a detrimental effect on BMD, in contrast with the positive weight-bearing effect. Body composition seems to be a more important determinant for bone health than simple body weight.

Diagnostic measures for sarcopenia and bone mineral density

SUMMARY

Currently used diagnostic measures for sarcopenia utilize different measures of muscle mass, muscle strength, and physical performance. These diagnostic measures associate differently to bone mineral density (BMD), as an example of muscle-related clinical outcome. These differences should be taken into account when studying sarcopenia.

INTRODUCTION

Diagnostic measures for sarcopenia utilize different measures of muscle mass, muscle strength, and physical performance. To understand differences between these measures, we determined the association with respect to whole body BMD, as an example of muscle-related clinical outcome.

METHODS

In the European cross-sectional study MYOAGE, 178 young (18-30 years) and 274 healthy old participants (69-81 years) were recruited. Body composition and BMD were evaluated using dual-energy X-ray densitometry. Diagnostic measures for sarcopenia were composed of lean mass as percentage of body mass, appendicular lean mass (ALM) as percentage of body mass, ALM divided by height squared (ALM/height(2)), knee extension torque, grip strength, walking speed, and Timed Up and Go test (TUG). Linear regression models were stratified for sex and age and adjusted for age and country, and body composition in separate models.

RESULTS

Lean mass and ALM/height(2) were positively associated with BMD (P < 0.001). Significance remained in all sex and age subgroups after further adjustment for fat mass, except in old women. Lean mass percentage and ALM percentage were inversely associated with BMD in old women (P < 0.001). These inverse associations disappeared after adjustment for body mass. Knee extension torque and handgrip strength were positively associated with BMD in all subgroups (P < 0.01), except in old women. Walking speed and TUG were not related to BMD.

CONCLUSIONS

The associations between diagnostic measures of sarcopenia and BMD as an example of muscle-related outcome vary widely. Differences between diagnostic measures should be taken into account when studying sarcopenia.

Effect of fat mass and lean mass on bone mineral density in postmenopausal and perimenopausal Thai women

BACKGROUND

The purpose of this study was to investigate the association between fat mass, lean mass, and bone mineral density (BMD) in postmenopausal and perimenopausal Thai women.

METHODS

A cross-sectional study was conducted in 1579 healthy Thai women aged 40-90 years. Total body, lumbar spine, total femur, and femoral neck BMD and body composition were measured by dual x-ray absorptiometry. To evaluate the associations between fat mass and lean mass and various measures of BMD, multivariable linear regression models were used to estimate the regression coefficients for fat mass and lean mass, first in separate equations and then with both fat mass and lean mass in the same equation.

RESULTS

Among the study population, 1448 subjects (91.7%) were postmenopausal and 131 (8.3%) were perimenopausal. In postmenopausal women, after controlling for age, height, and duration of menopause, both fat mass and lean mass were positively correlated with BMD when they were analyzed independently of each other. When included in the same equation, both fat mass and lean mass continued to show a positive effect, but lean mass had a significantly greater impact on BMD than fat mass at all regions except for total body. Lean mass but not fat mass had a positive effect on BMD at all skeletal sites except the lumbar spine, after controlling for age and height in perimenopausal women.

CONCLUSION

Lean mass had a significant beneficial effect on BMD in both postmenopausal and perimenopausal women and can be considered as one of the determinants of bone mass. The effect of the fat mass was related to menopausal status, but only demonstrated a positive impact in perimenopausal women.

Bone alterations in hepatitis C virus infected patients

BACKGROUND AND AIMS

Most studies have shown that patients with chronic hepatitis C virus (HCV) infection are affected by osteoporosis. However, liver function impairment and deranged nutrition may both play a role in the bone alterations observed. In some works no osteoporosis was found, and some cases of osteosclerosis have been reported. The aim of the study is to assess bone alterations in treatment-naïve, well-nourished HCV patients, in order to discern whether or not HCV infection causes osteoporosis.

METHODS

Whole-body bone densitometry and assessment of T-score at lumbar spine and hip were performed to 40 patients and 40 age- and sex-matched controls, with a Lunar Prodigy Advance (General Electric, Piscataway, NJ, USA). All the patients underwent liver biopsy. Nutritional evaluation was performed by subjective nutritional assessment, body mass index (BMI), and densitometric assessment of total lean mass and total fat mass. Serum osteocalcin, osteoprotegerin, RANKL, PTH, crosslaps, vitamin D3, testosterone, IGF-1, and estradiol were determined.

RESULTS

Patients did not show differences in total bone mineral density (BMD) or T-score with controls. On the contrary, about a third of them showed positive T scores. Patients showed lower IGF-1, vitamin D3 and testosterone, but higher telopeptide levels, and a trend to higher osteoprotegerin levels. Multivariate analyses disclosed that age, sex, and total lean mass were the only parameters independently related with BMD.

CONCLUSIONS

Therefore, chronic HCV infection in well nourished patients with preserved liver function does not cause osteoporosis.

Short-term lenalidomide (Revlimid) administration ameliorates cardiomyocyte contractile dysfunction in ob/ob obese mice

Lenalidomide is a potent immunomodulatory agent capable of downregulating proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and upregulating anti-inflammatory cytokines. Lenalidomide has been shown to elicit cardiovascular effects, although its impact on cardiac function remains obscure. This study was designed to examine the effect of lenalidomide on cardiac contractile function in ob/ob obese mice. C57BL lean and ob/ob obese mice were given lenalidomide (50 mg/kg/day, p.o.) for 3 days. Body fat composition was assessed by dual-energy X-ray absorptiometry. Cardiomyocyte contractile and intracellular Ca(2+) properties were evaluated. Expression of TNF-α, interleukin-6 (IL-6), Fas, Fas ligand (FasL), the short-chain fatty acid receptor GPR41, the NFκB regulator IκB, endoplasmic reticulum (ER) stress, the apoptotic protein markers Bax, Bcl-2, caspase-8, tBid, cytosolic cytochrome C, and caspase-12; and the stress signaling molecules p38 and extracellular signal-regulated kinase (ERK) were evaluated by western blot. ob/ob mice displayed elevated serum TNF-α and IL-6 levels, fat composition and glucose intolerance, the effects of which except glucose intolerance and fat composition were attenuated by lenalidomide. Cardiomyocytes from ob/ob mice exhibited depressed peak shortening (PS) and maximal velocity of shortening/relengthening, prolonged time-to-PS and time-to-90% relengthening as well as intracellular Ca(2+) mishandling, which were ablated by lenalidomide. Western blot analysis revealed elevated levels of TNF-α, IL-6, Fas, Bip, Bax, caspase-8, tBid, cleaved caspase-3 caspase-12, cytochrome C, phosphorylation of p38, and ERK in ob/ob mouse hearts, the effects of which with the exception of Bip, Bax, and caspase-12 were alleviated by lenalidomide. Taken together, these data suggest that lenalidomide is protective against obesity-induced cardiomyopathy possibly through antagonism of cytokine/Fas-induced activation of stress signaling and apoptosis.

Obstructive sleep apnea and bone mineral density in obese patients

CONTEXT

Obesity and its co-morbidities may adversely affect bone mineral density (BMD). Obstructive sleep apnea (OSA) is a major complication of obesity. To date, the effects of OSA on BMD in obese patients have been poorly studied.

OBJECTIVE

To examine whether the severity of OSA independently correlates with BMD in obese patients.

METHODS

One hundred and fifteen obese subjects with OSA (Apnea/Hypopnea Index [AHI] ≥5 events per hour) were included in the study. BMD was measured at lumbar spine, total hip, and femoral neck by dual energy X-ray absorptiometry. Body mass index, lean mass, and representative measures of metabolic syndrome (waist circumference, fasting plasma glucose, blood pressure, HDL-cholesterol, triglycerides) and inflammation (ESR, CRP, fibrinogen) were also evaluated.

RESULTS

BMD did not differ among obese individuals regardless of OSA severity. Correlation coefficient analysis for all the covariates showed a lack of association between AHI and BMD that was strongly influenced by age and weight.

CONCLUSION

Our study does not support an independent association between AHI and BMD in obese patients. Controlled studies involving a greater number of patients are warranted.