Abstract 1678: Plasma Osteocalcin: A Novel Marker of Insulin Resistance and Metabolic Syndrome in Adults With Hypertension
Background: Osteocalcin, a marker of bone formation, influences insulin secretion and sensitivity. We investigated whether plasma osteocalcin was associated with measures of insulin resistance, adipokine levels, and presence of metabolic syndrome (MetSyn).
Methods: Plasma osteocalcin was measured by solid phase sandwich immunoassay in 1324 African Americans (AA) (64±9 y; 73 % women) and 1237 non-Hispanic whites (NHW) (59±10 y; 56% women) belonging to hypertensive sibships. MetSyn was defined per Adult Treatment Panel III criteria. Generalized estimating equations were used, stratified by ethnicity, to assess whether plasma osteocalcin was associated with measures of insulin resistance, circulating levels of adiponectin and leptin, and MetSyn.
Results: The prevalence of MetSyn was 50% in AA and 49% in NHW. Plasma osteocalcin levels decreased with increasing number of metabolic syndrome components (Fig 1⇓). In each ethnic group, after adjustment for age and sex, osteocalcin levels were inversely correlated (P<0.05) with BMI, fasting glucose and insulin, HOMA-IR, triglycerides, and plasma leptin levels; and positively correlated with plasma adiponectin levels (P<0.001). In multivariable models that adjusted for age, sex, smoking, serum creatinine, statin and estrogen use, osteocalcin levels in the highest quartile were associated with a lower odds (OR) of having MetSyn compared to the bottom quartile: OR in AA, 0.35 (0.25– 0.48); OR in NHW, 0.47 (0.33– 0.67).
Conclusions: Plasma osteocalcin is associated with measures of insulin resistance, plasma levels of adipokines, and presence of MetSyn, suggesting a novel paradigm of cross talk between bone and adipose tissue.