The effects of adiponectin and leptin on changes in bone mineral density.
ABSTRACT We tested the hypothesis that low leptin and high adiponectin levels are associated with higher rates of bone mineral density (BMD) loss among 3,075 men and women, aged 70-79, from the Health Aging and Body Composition Study. Results suggest that adiponectin, but not leptin, is a risk factor for bone loss in women.
Adiponectin and leptin are hormones secreted by adipose cells that may impact BMD. Few studies have evaluated the longitudinal association of leptin and adiponectin levels with rates of BMD change.
Hip and whole-body areal BMD (aBMD) were measured five times using dual-energy X-ray absorptiometry over 10 years (average follow-up time, 7.95 ± 1.92 years). Trabecular lumbar spine volumetric BMD (vBMD) was measured using quantitative computed topography at baseline and year 6 in the Pittsburgh cohort only. Random slope and intercept models were used to account for within person correlation as a result of repeated measures of hip and whole-body aBMD. Linear regression was used to model changes in spine trabecular vBMD.
Among women, the annualized rate of hip aBMD loss in the highest tertile of adiponectin was -0.67% (95% CI -0.77, -0.58) compared to [-0.43% (95% CI -0.51, -0.35)] in the lowest tertile (p trend = 0.019) after adjusting for age, race, BMI, diabetes, baseline hip aBMD, and weight change. In men, hip aBMD loss was greatest in the high adiponectin group (tertile 3), however this association was not significant (p trend = 0.148). After adjusting for weight change in women, the association between higher leptin and lower hip aBMD loss was attenuated and no longer significant (p trend = 0.134). Leptin and adiponectin levels were not associated with whole-body aBMD or trabecular lumbar spine vBMD loss.
Adiponectin was associated with increased hip aBMD loss in women only, supporting evidence that adiponectin may have an important role in bone health.
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ABSTRACT: Adiponectin, a recently discovered adipocyte-derived peptide, is involved in the regulation of insulin sensitivity and lipid oxidation and, purportedly, in the development of atherosclerosis and coronary heart disease in humans. To assess prospectively whether plasma adiponectin concentrations are associated with risk of myocardial infarction (MI). Nested case-control study among 18 225 male participants of the Health Professionals Follow-up Study aged 40 to 75 years who were free of diagnosed cardiovascular disease at the time of blood draw (1993-1995). During 6 years of follow-up through January 31, 2000, 266 men subsequently developed nonfatal MI or fatal coronary heart disease. Using risk set sampling, controls were selected in a 2:1 ratio matched for age, date of blood draw, and smoking status (n = 532). Incidence of nonfatal MI and fatal coronary heart disease by adiponectin level. After adjustment for matched variables, participants in the highest compared with the lowest quintile of adiponectin levels had a significantly decreased risk of MI (relative risk [RR], 0.39; 95% confidence interval [CI], 0.23-0.64; P for trend <.001). Additional adjustment for family history of MI, body mass index, alcohol consumption, physical activity, and history of diabetes and hypertension did not substantively affect this relationship (RR, 0.41; 95% CI, 0.24-0.70; P for trend <.001). Further adjustment for hemoglobin A1c or C-reactive protein levels also had little impact, but additional adjustment for low- and high-density lipoprotein cholesterol levels modestly attenuated this association (RR, 0.56; 95% CI, 0.32-0.99; P for trend =.02). High plasma adiponectin concentrations are associated with lower risk of MI in men. This relationship can be only partly explained by differences in blood lipids and is independent of inflammation and glycemic status.JAMA The Journal of the American Medical Association 04/2004; 291(14):1730-7. · 30.03 Impact Factor
Article: Plasma leptin concentrations are associated with bone mineral density and the presence of vertebral fractures in postmenopausal women.[show abstract] [hide abstract]
ABSTRACT: Although total fat body mass (FM) is considered to be one of the major determinants of bone mass, the mechanism by which FM and bone mass are positively correlated remains unclear. Leptin, the product of the obese (ob) gene, is secreted from adipocytes and its plasma levels are known to be positively correlated with %fat (FM divided by total body weight). There is recent evidence suggesting that leptin directly stimulates osteoblastic differentiation. Thus it is possible that the anabolic action of this hormone on bone may participate in the positive correlation between FM and bone mass. In this study, we analysed the relationships between either plasma leptin levels or %fat vs. bone mineral density (BMD) values as well as the presence of vertebral compression fractures, and evaluated whether or not plasma leptin levels were associated with BMD or bone fragility in a manner independent of FM. One hundred and thirty-nine postmenopausal women (age 48-78 years, mean 62.5), who visited our outpatient clinic for the evaluation of osteoporosis. Plasma concentrations of leptin after an overnight fast were measured by radioimmunoassay. BMD values were measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine, femoral neck and whole body. Distal one-third of radius BMD was measured by single photon absorptiometry (SPA). Vertebral fractures were assessed by lateral thoracic and lumbar spine radiographs. Although neither plasma leptin levels nor %fat correlated with age, there was a significant positive correlation between plasma leptin levels and %fat (r = 0.563, P < 0.001). Plasma leptin levels were significantly and positively correlated with BMD values at all skeleton sites measured, and multiple regression analysis revealed that this positive relationship was still observed with BMD values of the femoral neck and of the whole body, even after %fat and age were taken into account. Moreover, plasma leptin levels but not %fat were significantly lower in women with vertebral fractures than in those without fractures. When multiple logistic regression analysis was performed with either plasma leptin value or %fat employed as independent variables, plasma leptin values but not %fat were selected as an index affecting the presence of vertebral fractures. Our study showed that plasma leptin levels but not %fat are associated with BMD and the presence of vertebral fractures in postmenopausal women, suggesting that circulating leptin might play a physiological role in maintaining bone mass as well as better bone quality.Clinical Endocrinology 09/2001; 55(3):341-7. · 3.17 Impact Factor
Article: Relationship of serum leptin concentration with bone mineral density in the United States population.[show abstract] [hide abstract]
ABSTRACT: Overweight is associated with both higher bone mineral density (BMD) and higher serum leptin concentrations. In humans, little is known about the relationship of leptin concentration and bone density. We studied this relationship in a large, national population-based sample. Participants included 5815 adults in the Third U.S. National Health and Nutrition Examination Survey (NHANES III; 1988-1994) who underwent DXA of the proximal femur and measurement of fasting serum leptin. Mean +/- SE BMD (gm/cm2) of the total hip was 1.01 +/- 0.005 in men, 0.94 +/- 0.004 in premenopausal women, and 0.78 +/- 0.007 in postmenopausal women. Bone density increased with increasing leptin concentration in men (p = 0.003), premenopausal women (p < 0.001), and postmenopausal women (p < 0.001). However, after adjusting for body mass index (BMI) and other bone density-related factors, an inverse association emerged in men (p < 0.001), being most evident among men < 60 years old. There was no association of leptin and BMD in premenopausal women (p = 0.66) or postmenopausal women (p = 0.69) in multivariate analysis. Controlling for leptin had no effect on the strong positive association of BMI and BMD in either men or women. Serum leptin concentration did not appear to affect directly BMD. If present, the association appeared to be limited to younger men who are at lower risk of osteoporosis.Journal of Bone and Mineral Research 10/2002; 17(10):1896-903. · 6.37 Impact Factor