Longitudinal Study of Body Composition of 101 HIV Men With Lipodystrophy: Dual-Energy X-Ray Criteria for Lipodystrophy Evolution

The aim of this study was to define evolution profiles of body composition among human immunodeficiency virus (HIV)-infected men with lipodystrophy. The design is a retrospective analysis using observational data collected longitudinally. We included 101 HIV-infected men with lipodystrophy managed in routine practice and who had 2 dual energy X-ray absorptiometry scans within a minimum interval of 18 mo. Lipodystrophy was defined as a fat mass ratio (FMR, defined as the ratio of the percentage of the trunk fat mass over the percentage of the lower limbs fat mass) equal or superior to 1.5. Patients were classified in “improved” group (IG: increase of lower limbs fat mass ≥ 10%) or “nonimproved” group (NIG). Body composition, immunovirological and epidemiological data were collected and compared between the 2 groups. In the whole population, over a 4-yr period, a significant increase was observed for total fat mass, trunk fat mass, and lower limbs fat mass, whereas total lean mass was stable. Total body mineral density decreased. Fifty-nine patients (IG), less exposed to zidovudine than the NIG, had an increase of lower limbs fat mass higher than 10%. But only 13 (22%) regained a normal distribution of fat mass (FMR < 1.5), showing that lipodystrophy was slowly reversible. Among the NIG, 5 patients (11.9%), less exposed to zidovudine and with a higher mean of viral load, reached an FMR below 1.5. It was mainly because of a loss of trunk fat mass, which could be the sign of a lipodystrophy worsening. Lipodystrophy improved for 58.4% of men. The improvement was very slow. Recovery was observed only in patients with an earlier intervention. No correlation was observed between lipodystrophy and total body bone mineral density. The loss of trunk fat mass without gain of lower limbs fat mass may indicate a worsening of HIV disease.     

Fat Mass Ratio: An Objective Tool to Define Lipodystrophy in HIV-Infected Patients Under Antiretroviral Therapy

Human immunodeficiency virus (HIV) infection and its treatment with antiretroviral therapy (ART) have been associated with lipodystrophy. Different clinical methodologies have been used to define the syndrome. The aim of this study was to propose gender-specific reference values using objective measurements for defining lipodystrophy in HIV-infected patients. Using dual-energy X-ray absorptiometry (DXA), total body composition was analyzed in 221 HIV-infected patients under ART (146 men). We used fat mass ratio (FMR) as the ratio between the percent of the trunk fat mass and the percent of the lower-limb fat mass. One hundred forty patients (63.6%) presented clinically defined lipodystrophy. In men, the optimal cutoff value for the FMR was 1.961 (area under the receiver operating characteristic curve [AUC]: 0.74 [95% confidence interval (CI): 0.66–0.82], p < 0.001), with a sensitivity 58.3%, a specificity 83.7%, a positive predictive value (PPV) of 89.6% and a negative predictive value (NPV) of 45.5%. In women, the optimal cutoff value for the FMR was 1.329 (AUC: 0.74 [95% CI: 0.63–0.86], p < 0.001), with a sensitivity 51.4%, a specificity 94.6%, a PPV of 90.5%, and an NPV of 66.0%. The FMR evaluated by DXA with the gender-specific cutoffs defined here is an objective way to define HIV-related lipodystrophy.     

BMD is reduced in HIV-infected men irrespective of treatment.

Osteoporosis has be reported to be a complication of active antiretroviral therapy of HIV infection. We studied 148 HIV-infected men stratified according to their treatment. Our data show that these patients have an average 9% decreased BMD, irrespective of their treatment. Low body mass index and high resorption markers were associated with low bone density. INTRODUCTION: Osteoporosis has been reported in HIV-infected (HIV+) patients, and it has been suggested that it may be linked to protease-inhibitor treatments (PI). MATERIALS AND METHODS: To assess this risk and to investigate its putative link with treatments, we compared the bone density of HIV+ men, who were either receiving treatment (including PI [PI+], n = 49; without PI [PI-], n = 51) or untreated (UT, n = 48). We included 81 age-matched control HIV-negative (HIV-) males (age, 40 +/- 8 years). RESULTS: BMD adjusted for age (Z-score) was lower in the HIV+ patients at the lumbar spine (HIV+: -1.08 +/- 1.21, HIV-: -0.06 +/- 1.26, p < 0.001) and the femoral neck (HIV+: -0.39 +/- 1.05, HIV-: 0.25 +/- 0.87, p < 0.001). The prevalence of osteoporosis was 16% in HIV+ and 4% in HIV- subjects (p < 0.01). In the HIV+ subjects, the Z-score was correlated only to body mass index (r = 0.27 at lumbar spine and 0.35 at femoral neck). Untreated HIV+ patients had a negative Z-score (-0.82 +/- 1.15 for the lumbar spine), which was not different from the one of treated HIV+ patients. In the PI+ and PI- groups, the Z-score did not depend on the presence of lipodystrophy or the proportion of fat in the abdomen and legs measured by DXA. Markers of bone remodeling were measured in the 132 HIV+ and 35 HIV- subjects. Compared with controls, HIV+ patients had lower bone alkaline phosphatase and higher urinary cross-laps/Cr, which was negatively correlated with the Z-score at both the femoral neck (r = -0.22) and lumbar spine (r = -0.21). TNFalpha was increased in untreated compared with treated HIV+ subjects and was not correlated to the Z-score. CONCLUSION: Our cross-sectional study does not show any deleterious effect of the treatment but does indicate a decrease in bone density in HIV+ patients irrespective of the treatment. This low bone density is in part related to the low body weight and is associated with increased bone resorption.     

Impact of HIV Infection on Total Body Composition in Treatment—Naive Men Evaluated by Dual-Energy X-ray Absorptiometry Comparison of 90 Untreated HIV-Infected Men to 241 Controls

The aim of this study was to establish the contribution of human immunodeficiency virus (HIV) itself on body composition changes evaluated by dual-energy X-ray absorptiometry (DXA). Body composition evaluated by DXA in 90 HIV never treated men, without comorbidity, or current or past opportunistic infections were compared with 241 healthy volunteers. The mean duration of seropositivity from HIV diagnosis was 41 ± 62 mo, mean CD4 and viral load at the time of DXA were 402/mm³ ± 263 (control values 500–1200/mm³) and 4.2 log copies/mL ± 1.3. Mean age (41 vs 39 yr, respectively, for HIV never treated patients and controls) and mean height (174.5 vs 176 cm) were not different, but mean weight was lower among HIV never treated patients (69.8 vs 78.7 kg). Mean total body bone mineral density (BMD) of naive HIV-infected patients was lower than that of controls (1.20 vs 1.23 g/cm², p = 0.01) but not after adjustment on age, height, lean mass (LM), and fat mass ratio (FMR = % trunk fat mass/% lower limb fat mass). Fat mass (13.2 vs 16.5 kg, p < 0.0001) and LM (53.5 vs 59 kg, p < 0.0001) of naive HIV-infected patients were lower whatever the adjustment variables. The FMR was lower in naive HIV-infected men (1.0 vs 1.3, p < 0.0001) because of a decreased trunk fat mass. After adjustment on age, height, LM, and fat mass, the lower limbs fat mass percentage was higher in HIV-infected men. The profile of naïve HIV-infected patients displayed low lean and fat masses, and a fat mass repartition characterized by a predominant loss in the trunk. Those alterations may result from the catabolic effect of the chronic HIV infection.     

Hip bone geometry in HIV/HCV-co-infected men and healthy controls

Summary

People with both HIV and hepatitis C are more likely than those with HIV alone to have wrist, hip, and spine fractures. We compared hip strength between HIV/HCV-co-infected men and healthy men and found that HIV/HCV-co-infected men had decreased hip strength due to lower lean body mass.

Introduction

Hepatitis C co-infection is a risk factor for fragility fracture among HIV-infected populations. Whether bone strength is compromised in HIV/HCV-co-infected patients is unknown.

Methods

We compared dual-energy x-ray absorptiometry (DXA)-derived hip geometry, a measure of bone strength, in 88 HIV/HCV-co-infected men from the Johns Hopkins HIV Clinic to 289 men of similar age and race and without HIV or HCV from the Boston Area Community Health Survey/Bone Survey. Hip geometry was assessed at the narrow neck, intertrochanter, and shaft using hip structural analysis. Lean body mass (LBM), total fat mass (FM), and fat mass ratio (FMR) were measured by whole-body DXA. Linear regression was used to identify body composition parameters that accounted for differences in bone strength between cohorts.

Results

HIV/HCV-co-infected men had lower BMI, LBM, and FM and higher FMR compared to controls (all p?p?Conclusion HIV/HCV-co-infected men have compromised hip strength at the narrow neck compared to uninfected controls, which is attributable in large part to lower lean body mass.     

HIV-Infected Patients With and Without Lipodystrophy Under Combined Antiretroviral Therapy: Evaluation of Body Composition

In HIV-infected patients, combined antiretroviral therapy (cART) is associated to adipose tissue redistribution known as lipodystrophy and associated cardiometabolic risk. This study aimed to evaluate the evolution of body composition in HIV-infected patients, with and without lipodystrophy, over 2?yr. We evaluated anthropometric parameters and body composition by whole-body dual-energy X-ray absorptiometry in 144 HIV-infected patients on cART. We defined lipodystrophy by fat mass ratio. Lipodystrophy was present in 45.77% of the patients. These patients presented higher HIV infection duration, cART duration, and CD4+ cell count, with no differences regarding gender, age, body mass index, and viral load. Patients with lipodystrophy showed an increase in total fat mass (9.9%) and upper-limbs fat mass (17.6%), with a decrease in total, trunk, and lower-limbs fat-free mass (2.2%; 2.2%, and 3.9%, respectively), over 2?yr. In patients without lipodystrophy, the trunk fat-free mass decreased 1.9% over time, and no changes were observed in the other studied parameters. In patients with lipodystrophy, there was predominantly a central fat mass gain, with no changes in lower limbs, suggesting that peripheral adipocytes lose their regenerative capacity.     

Altered myocellular and abdominal fat partitioning predict disturbance in insulin action in HIV protease inhibitor-related lipodystrophy

HIV protease inhibitor-related lipodystrophy is characterized by peripheral fat loss, hyperlipidemia, and insulin resistance. Increased availability of lipid to muscle may be one of the mechanisms that induce insulin resistance. Regional fat, intramyocellular lipid (by (1)H-magnetic resonance spectroscopy), serum lipids, and insulin-stimulated glucose disposal (by hyperinsulinemic-euglycemic clamp) were quantified in 10 men who had HIV-1 infection with moderate to severe lipodystrophy and a control group of 10 nonlipodystrophic men who had HIV-1 infection and were na?ve to protease inhibitors to examine the effects of lipodystrophy on glucose and lipid metabolism. Lipodystrophic subjects showed lower insulin-stimulated glucose disposal than control subjects (P = 0.001) and had increased serum triglycerides (P = 0.03), less limb fat (P = 0.02), increased visceral fat as a proportion of total abdominal fat (P = 0.003), and increased intramyocellular lipid (1.90 +/- 0.15 vs. 1.23 +/- 0.16% of water resonance peak area; P = 0.007). In both groups combined, visceral fat related strongly to intramyocellular lipid (r = 0.83, P < 0.0001) and intramyocellular lipid related negatively to insulin-stimulated glucose disposal (r = -0.71, P = 0.0005). Fasting serum cholesterol and triglycerides related positively to intramyocellular lipid and visceral fat in lipodystrophic subjects only. The data indicate that lipodystrophy is associated with increased lipid content in muscle accompanying impaired insulin action. The results do not establish causation but emphasize the interrelationships among visceral fat, myocyte lipid, and insulin action.     

Diabetes is associated independently of body composition with BMD and bone volume in older white and black men and women: The Health, Aging, and Body Composition Study.

The association between type 2 diabetes, BMD, and bone volume was examined to determine the effect of lean and fat mass and fasting insulin in the Health, Aging, and Body Composition Study, which included white and black well-functioning men and women 70-79 years of age (N = 2979). Diabetes predicted higher hip, whole body, and volumetric spine BMD, and lower spine bone volume, independent of body composition and fasting insulin. INTRODUCTION: The purpose of this study was to determine if the association between type 2 diabetes and higher BMD observed in older white women is seen in elderly white men and blacks and to evaluate if higher BMD in diabetic individuals is accounted for by lean mass, fat mass, or fasting insulin differences. MATERIALS AND METHODS: In the Health, Aging, and Body Composition Study, which included white and black well-functioning men and women 70-79 years of age (N = 2979), 19% of participants had diabetes at baseline. Of those with diabetes, 57% were men, and 62% were black. Multivariate linear regression models examined independent effects of diabetes, lean mass, fat mass, visceral fat, and fasting insulin on BMD and bone volume while adjusting for relevant covariates. RESULTS AND CONCLUSIONS: Fasting insulin, visceral fat, and volumetric spine BMD, assessed by CT, and lean mass, fat mass, and total hip and whole body BMD, assessed by DXA, were higher (p < or = 0.05 for all) for those with diabetes. Hip BMD was higher in white men (0.99 +/- 0.14 versus 0.93 +/- 0.14 g/cm2, p < 0.001), black men (1.06 +/- 0.17 versus 1.00 +/- 0.15 g/cm2, p < 0.001), white women (0.83 +/- 0.13 versus 0.76 +/- 0.13 g/cm2, p < 0.001), and black women (0.90 +/- 0.15 versus 0.85 +/- 0.15 g/cm2, p < 0.001) with diabetes compared with those without diabetes, although the relationship was attenuated by body composition. In multiple regression models, diabetes was an independent predictor of higher hip, whole body, and volumetric spine BMD in all participants (p < or = 0.001), but lower spine volume (p = 0.01) and higher hip BMD for each race-gender group (p < or = 0.01). Type 2 diabetes was associated with a 4-5% higher total hip BMD in all race-gender groups of elderly adults, independent of body composition and fasting insulin levels.     

Risk factors for decreased bone density and effects of HIV on bone in the elderly

SUMMARY: Most studies of bone density in HIV-infected individuals focus on young men. This study compares differences in bone density in elderly HIV positive men and women to HIV negative controls. Bone density was lower in the lumbar spine and hip in the HIV-infected group. Antiretrovirals may be associated with decreased bone mineralization. INTRODUCTION: Individuals with human immunodeficiency virus (HIV) may be at increased risk for osteoporosis. Prolonged exposures to HIV and/or antiretroviral therapy are possible causes for this association. This study compares differences in bone mineral density (BMD) in elderly HIV positive men and women to HIV negative controls. METHODS: A cross-sectional study was conducted among 57 HIV-infected and 47 HIV negative subjects over age 55. BMD at the lumbar spine and total hip and markers of bone turnover were compared. RESULTS: BMD was borderline lower in the lumbar spine and significantly lower in the hip in the HIV-infected group. Controlling for age, sex, race and body mass index, differences between the groups were significant at both sites. There was no difference in markers of bone turnover between the groups. Tenofovir use was significantly associated with decreased BMD at the spine while protease inhibitor use was significantly associated with decreased BMD at the hip. CONCLUSION: Elderly men and women with HIV have lower bone mass than HIV negative controls. Decreased body mass index was the most important risk factor associated with decreased BMD. Bone demineralization was observed among HIV-infected subjects receiving either tenofovir or a protease inhibitor.     

Adipose tissue and volumetric bone mineral density of older Afro‐Caribbean men

Although low body weight is a risk factor for osteoporosis‐related fractures, conflicting data exist for the association between adiposity and bone mineral density (BMD). Studies examining these relationships have measured body fat and BMD with dual‐energy X‐ray absorptiometry (DXA), which cannot distinguish subcutaneous adipose tissue area (SAT) from total adiposity or trabecular from cortical bone. To investigate the relationship between adiposity and BMD further, we analyzed body composition and adipose tissue distribution by quantitative computed tomography (QCT) in 1829 Afro‐Caribbean men aged 40 years and older from a population‐based sample. Cortical volumetric BMD, muscle cross‐sectional area, total adipose tissue area (TAT), and percentage SAT were measured at the proximal tibia. Trabecular volumetric BMD was measured at the distal tibia. We used analysis of covariance to test for associations between quartile of the adipose tissue measures and BMD, adjusting for anthropometric, health, and lifestyle factors. Higher TAT was associated with lower cortical BMD in both unadjusted and adjusted models (p < .001). Men with a higher percentage SAT had greater cortical BMD (p < .001). Similar associations were seen between percent SAT and trabecular BMD at the distal tibia. These results indicate that total adiposity is a potentially important correlate of bone mass in older men and that different fat depots may have opposing associations with bone mass. Additional research is needed to better understand the mechanisms underlying the relationship between body fat distribution and bone mass. © 2010 American Society for Bone and Mineral Research.     

正常体重中年人体脂含量与腰椎和髋部骨密度相关性研究

目的探讨正常体重中年人体脂含量与腰椎和髋部骨密度(bone mineral density,BMD)相关性。方法选取499名成年受试者(平均年龄48.7岁),通过双能X线吸收测定法测量受试者BMD和体脂含量,采用多元线性回归分析和协方差分析评估BMD与体脂含量之间的关联。结果按体脂百分比截止值进行分组。体质量指数为18.5～22.9 kg/m2的男性临界值分别为20.6%和25.7%,而女性的临界值分别为33.4%和36%。体脂百分比往往与BMD呈负相关。身体脂肪百分比的增加与正常体重中年人的BMD降低有关。正常体重人群体脂百分比对BMD的影响在男性中比女性更明显。结论体重正常的中年男性和女性体脂百分比与骨密度呈负相关,这种关联在男性中比在女性中更为突出。     

Role of serum leptin, insulin, and estrogen levels as potential mediators of the relationship between fat mass and bone mineral density in men versus women

Although fat mass is related to bone mineral density (BMD), the potential mechanism(s) of this effect remain to be defined. Thus, we assessed the role of the candidate hormones, leptin, insulin, and estrogen in mediating fat mass effects on the skeleton. Specifically, we related these hormones and fat mass to BMD at the total hip, mid-lateral spine, and mid-distal radius in a sample of 137 premenopausal women (age range 21-54 years), 165 postmenopausal women (34-93 years), and 343 men (23-90 years) recruited from the general population. Fat mass and BMD were significantly related in pre- and postmenopausal women at multiple sites, whereas this relationship was only weakly present in men at the total hip. Serum leptin levels were also significantly related to BMD in the women, but not in the men. Insulin was associated with hip BMD in the women, and bioavailable estradiol (E2) was correlated with BMD at all sites in men and in postmenopausal women. In the women, adjusting for leptin reduced the strength of the association between fat mass and BMD, with further adjustments for insulin or bioavailable E2 having no additional effects. Adjusting for leptin in the men had no consistent effect on the relationship between fat mass and BMD. Collectively, these data suggest that there is a sexual dimorphism in the relationship of fat mass and leptin to BMD, with both being positively associated with BMD in women but not in men. In women, leptin may also mediate at least part of the protective effect of fat mass on the skeleton.     

Relative contribution of body composition to bone mineral density at different sites in men and women of South Korea

We examined the relative contribution of body composition to bone mineral density (BMD) at various sites in 1406 Korean rural men and women, aged 19–80 years, from July to August 2004. The BMD was measured at peripheral (distal forearm and calcaneus) and central (lumbar spine at L1–L4, femoral neck, trochanter, and Ward's triangle) using dual-energy X-ray absorptiometry. In multivariate analyses, the linear regression models were adjusted for relevant covariates. In premenopausal women, only lean mass had a significant positive correlation with BMD at all sites. In postmenopausal women, fat mass was significantly positively correlated with BMD at all sites, except the Ward's triangle; fat mass was the only determinant of BMD at the lumbar, distal forearm, and calcaneus sites, whereas both lean and fat mass contributed to BMD at the hip, with the effect of lean mass being slightly greater than that of fat mass. In younger men, lean mass had a significant positive contribution to BMD at all sites, whereas fat mass appeared to contribute negatively to BMD at all sites, except the calcaneus. In older men, lean mass made a significant positive contribution to the BMD at all sites; fat mass also made a significant positive contribution to the BMD at the forearm and calcaneus. These data indicate that in the Korean rural population, lean mass may be an important determinant of the BMD, whereas fat mass may contribute positively to BMD only in postmenopausal women and older men.     

Fat Mass Ratio in Brazilian HIV-infected Patients Under Antiretroviral Therapy and Its Relationship With Anthropometric Measurents

Introduction: Human immunodeficiency virus-related lipodystrophy is characterized by a variety of phenotypes and metabolic changes; however, consensus has not yet been reached on its diagnostic criteria. Different cutoff values for fat mass ratio have been proposed for this specific population as an objective diagnostic criterion for lipodystrophy. This study aimed to establish sex-specific reference values for fat mass ratio and to correlate them with anthropometric measurements for the diagnosis of human immunodeficiency virus-related lipodystrophy. Methodology: A cross-sectional study was performed on 189 human immunodeficiency virus-infected patients under antiretroviral therapy. Anthropometric measurements were evaluated, and body composition was determined using dual-energy X-ray absorptiometry. Fat mass ratio was calculated as the ratio of the percentage of the trunk fat mass and the percentage of the lower limb fat mass. Results: One hundred and thirty-two patients (69%) presented lipodystrophy by objective criteria. In men, the cutoff for the fat mass ratio was 1.55 (area under the receiver operating characteristic curve: 0.73 [95% confidence interval: 0.62–0.83], p = 0.000008), with a sensitivity of 62.5%, a specificity of 70.5%, a positive predictive value of 77.8%, and a negative predictive value of 53.4%. In women, the cutoff for the fat mass ratio was 0.959 (area under the receiver operating characteristic curve: 0.70 [95% confidence interval: 0.56–0.85], p = 0.03), with a sensitivity of 83.60%, a specificity of 61.5%, a positive predictive value of 90.2%, and a negative predictive value of 47.1%. Fat mass ratio was positively correlated with waist circumference (men: r = 0.246, p = 0.019; women: r = 0.302, p = 0.014) and neck circumference (men: r = 0.304, p = 0.004; women: r = 0.366, p = 0.003) in both sexes; and body mass index (r = 0.288, p = 0.006) and waist-hip ratio (r = 0.288, p = 0.006) in men. Conclusion: The fat mass ratio evaluated using dual-energy X-ray absorptiometry with the sex-specific cutoffs is an objective tool to define human immunodeficiency virus-related lipodystrophy.     

Long-term HIV infection and antiretroviral therapy are associated with bone microstructure alterations in premenopausal women

Summary

We evaluated the influence of long-term HIV infection and its treatment on distal tibia and radius microstructure. Premenopausal eumenorrheic HIV-positive women displayed trabecular and cortical microstructure alterations, which could contribute to increased bone fragility in those patients.

Introduction

Bone fragility is an emerging issue in HIV-infected patients. Dual-energy X-ray absorptiometry (DXA) quantified areal bone mineral density (BMD) predicts fracture risk, but a significant proportion of fracture risk results from microstructural alterations.

Methods

We studied the influence of long-term HIV infection on bone microstructure as evaluated by high-resolution peripheral quantitative computed tomography (HR-pQCT) in 22 HIV-positive (+ve) premenopausal eumenorrheic women and 44 age- and body mass index (BMI)-matched HIV-negative (?ve) controls. All subjects completed questionnaires regarding calcium/protein intakes and physical activity, and underwent DXA and HR-pQCT examinations for BMD and peripheral skeleton microstructure, respectively. A risk factor analysis of tibia trabecular density using linear mixed models was conducted.

Results

In HIV+ve women on successful antiretroviral therapy (undetectable HIV-RNA, median CD4 cell count, 626), infection duration was 16.5?±?3.5 (mean ± SD)?years; median BMI was 22 (IQR, 21–26)?kg/m². More HIV+ve women were smokers (82 versus 50 %, p?=?0.013). Compared to controls, HIV+ve women had lower lumbar spine (spine T-score ?0.70 vs ?0.03, p?=?0.014), but similar proximal femur BMD. At distal tibia, HIV+ve women had a 14.1 % lower trabecular density and a 13.2 % reduction in trabecular number compared to HIV?ve women (p?=?0.013 and 0.029, respectively). HR-pQCT differences in distal radius were significant for cortical density (?3.0 %; p?=?0.029).

Conclusions

Compared with HIV?ve subjects, premenopausal HIV+ve treated women had trabecular and cortical bone alterations. Adjusted analysis revealed that HIV status was the only determinant of between group tibia trabecular density differences. The latter could contribute to increased bone fragility in HIV+ve patients.     

The differential relationship between fat mass and bone mineral density by gender and menopausal status

Osteoporosis and obesity are important public health problems in an aging society. We investigated the differential impacts of fat on bone mineral density (BMD) according to gender and menopausal status. We analyzed the baseline data of an ongoing observational cohort study, including a total of 502 healthy subjects 20–88 years of age (144 men, 159 premenopausal women, 199 postmenopausal women). Body composition and fat mass were measured using computed tomography and dual energy X-ray absorptiometry (DXA). BMD was measured at lumbar spines using DXA. In men and postmenopausal women, there was no significant correlation between fat and bone parameters after adjusting for age and body weight. However, in premenopausal women, BMD had significant negative correlations with waist circumference, total fat area, subcutaneous fat area, appendicular fat mass and percentage fat mass after adjusting for age and body weight. Furthermore, only in premenopausal women, the subjects with the highest quartile of percentage fat mass had the lowest BMD even after adjusting for confounding factors including age, body weight, physical activity, alcohol use and smoking history. Multiple linear regression analysis showed that percentage fat mass was a significant negative decisive factor for BMD in premenopausal women. Our study showed the differential relationship between fat mass and BMD according to gender and menopausal status. Only in premenopausal women did fat mass have a significant negative effect on bone mass. This result suggests the importance of reducing fat mass in order to achieve peak bone mass in young adult women.     

Anthropometrics and biochemical markers in men.

The relation between anthropometric components and biochemical markers has not been previously studied. To clarify the role of anthropometric factors in bone metabolism in men, 145 randomly selected subjects 40 to 70 yr of age from a population-based cohort were studied. Pearson's r and multiple regression analysis were used to assess the relation between anthropometrics (weight, body mass index [BMI], percentage of body fat, fat-free weight, and fat freeBMI), biochemical markers, and bone mineral density (BMD) at the spine and femoral neck, as well as between BMD and each biochemical marker (serum bone formation marker procollagen amino-terminal propeptide [PINP],urinary bone resorption marker amino-terminal telopeptide [NTx], and the ratio of PINP to NTx. Of the anthropometric factors, fat-free BMI had the highest association with the markers (r = -0.21 to -0.35, p < 0.05) and explained a higher percent of both spine BMD and NTx variance than weight. Body fat did not correlate with the BMD measures.Urinary NTx was a better indicator of current BMD status than PINP or the ratio of PINP to NTx, with the highest association with BMD at the sites tested (r = -0.20 to -0.29). NTx levels were statistically significantly different between men with normal and osteoporotic BMD at the femoral neck.     

Bone mineral density in hypogonadal men remains low after long—term testosterone replacement

AIM: In 11 congenital hypogonadal men, the bone mineral density (BMD) values were determined to assess the effect of long-term androgen replacement therapy (ART) on skeletal integrity. METHODS: Eleven congenital hypogonadal men, including 8 isolated gonadotropin deficiency patients, 2 Kallmann's syndrome and 1 vanishing testes syndrome were recruited and treated with 250 mg of testosterone enanthate intramuscularly every 4 weeks for 7-43 years (mean+/-SD: 21.5 +/-13 years). In these patients and a group of 10 healthy young men (controls), the whole and trabecular BMDs were examined at the distal end of radius by means of a peripheral quantitative computerized tomography device. RESULTS: The whole radial BMD in hypogonadal men was significantly less in the patients than in the healthy men (498+/-115 and 725+/-134 mg/cm(3), respectively; P<0.01); the trabecular BMD was also lower in the hypogonadal men (199+/-80 and 375+/-89 mg/cm(3); P< 0.01). The whole radial BMD values in 10 of 11 hypogonadal men were at least 1 SD below the mean value for healthy young men; 2 hypogonadal men had BMD values more than 2.5 SD lower than the healthy mean. Additionally, the whole radial BMD showed a significant negative correlation with the patient's age at the initiation of ART (r = 0.748, P<0.01). The serum level of bone-specific alkaline phosphatase and the urinary level of deoxypyridinoline were not significantly different between the two groups. CONCLUSION: Osteopenia persists in the hypogonadal men after long-term ART, suggesting that such patients have a persistent defect in bone development not alleviated by androgen replacement.     

Body composition changes with age have gender-specific impacts on bone mineral density

Body weight, smoking, alcohol, physical activity, and diet have been proven to affect bone mineral density (BMD) directly or indirectly. Of these, body weight is perhaps best known to affect BMD. However, there is some debate as to whether lean body mass (LBM) or fat mass (FM), the two components of body weight, most determines BMD. Recently, newer peripheral densitometry devices have been developed, which have the advantages of low cost and portability, and this has made field epidemiologic study of osteoporosis possible. As the number of studies that have focused on the contribution made by body composition to BMD is limited, we investigated the relative contribution of LBM and FM to BMD in healthy Korean subjects. 402 age- and weight-matched subjects over 45 years old were selected from a population-based cohort. The mean ages of men and women were 64.1 +/- 8.7 (mean +/- SD) and 64.2 +/- 12.7 years, and mean weights were 63.0 +/- 8.2 and 63.1 +/- 8.2 kg, respectively. BMD was measured by peripheral dual-energy X-ray absorptiometry (DEXA) and body composition by bioelectrical impedance. Sociodemographic characteristics and physical activities were investigated using a standard questionnaire delivered by face-to-face interview. BMDs were 0.48 +/- 0.01 and 0.37 +/- 0.11 g/cm2 in men and women, respectively. In men, age, weight, body mass index (BMI), LBM, FM, physical activity, smoking, alcohol, and education were significantly correlated with BMD. In women, age, weight, BMI, LBM, FM, education, years since menopause, number of deliveries, and number of children breast-fed were significantly correlated with BMD. By multiple regression, LBM, education, smoking, and alcohol in men, and age, LBM, FM, smoking, and number of delivery in women were independent determinants of BMD. LBM was an important contributor for BMD in men, but both LBM and FM were equally important contributors in female to BMD. This stems from the fact that body composition changes with age differ in men and women. Thus, the augmentation of muscle mass in men and the maintenance of an optimal weight in women act to prevent osteoporosis.     

Association between level of frailty and bone mineral density in community-dwelling men.

The goal of this study is to determine the associations between the components of a frailty definition and bone mineral density (BMD) in older men. A total of 392 community dwelling men (age range: 58-95 yr) with a mean age of 73+/-8 yr were evaluated. Femoral neck BMD T-scores ranged from -5.78 to +2.50, with 48.7% who had T-scores between -1 and -2.5 (low bone mass) and 8.7% who had T scores < or = -2.5 (osteoporosis). Participants were characterized as normal (39%), intermediate (55%), or frail (6%). Hand grip strength was 31.5+/-9.1 kg in those with normal BMD compared with 26.5+/-7.9 kg in those with osteoporotic BMD (p=0.0026). Walk speed (8 ft) was 2.32+/-0.49 s in those with normal BMD compared with 2.87+/-1.30 s with osteoporotic BMD (p=0.0015). Femoral neck T-score declined significantly with increasing level of frailty (p=0.014), but significance of decline was lost when corrected for age. Increasing frailty was associated with lower femoral neck BMD, although the association was not independent of age. Two components of the frailty model (i.e., hand grip strength and walking speed) were independently associated with lower femoral neck BMD, a finding that has not previously been reported in men.