Obesity and osteoporosis are two of the main common chronic diseases in women. Both are interconnected and contribute to glucose homeostasis. The objective of this study was to evaluate the effect of BMI on serum levels of total (OC) and undercarboxilated osteocalcin (ucOC), in 100 non diabetic overweight or obese adult women. Women were divided according BMI (range 25.0 to 52.8 kg/m2) into quartiles, and according to their menopausal status: premenopausal (PreM: ≤45 y; n=33), perimenopausal (PeriM: 46–54 y; n=18), postmenopausal (PostM: 55–65 y; n=34) and late menopausal (LM: >65 y; n=15). Total OC, ucOC and leptin were determined by ELISA kits. There were not significant differences between PreM and PostM from the same BMI quartile both in OCn and ucOCn. No significant changes were found in total OC mean values among BMI quartiles in either PreM or PostM (From the 1st to 4th quartiles: PreM: 37.5±3.0; 33.9±9.9; 27.2±12.2 and 25.1±17.4 ng/ml; PostM: 35.9±13.2; 43.6±21.5; 28.5±12.8; 28.3±16.3). In both menopausal status, the mean OCn levels presented a tendency to have lower values in the 3rd and 4th quartiles as compared to the 1st and 2nd. Conversely, there was a significant increase in ucOC mean levels as BMI increase, both in PreM and in PostM groups (from 1st to 4th quartiles: PreM: 1.53±1.08; 1.93±1.25; 3.25±1.72 and 4.27±0.86 ng/ml; ANOVA P=0.0003, Tuckey post‐test: P<0.01 between 1st and 4th and between 2nd and 4th quartiles; PostM: 1.09±1.04; 1.88±1.62; 2.74±1.51; 4.21±1.83; ANOVA P=0.0009, Tuckey post‐test: P<0.001 between 1st and 4th and P<0.05 between 2nd and 4th). Leptin levels also increased with BMI in both PreM and PostM.ConclusionThe present results confirm that BMI presents a significant influence on OC decarboxylation through leptin levels. Moreover, as ucOC is involved in glycemic control, the present results suggest that glucose homeostasis is affected by the increase in BMI.Support or Funding InformationSupported by Universidad de Buenos Aires, UBACyT 20720130100006BA