Endocrine Abstracts

Background /aim: Osteoporosis is a generalized bone disease, characterized by impaired bone firmness, resulting in an increased predisposition for fractures. In order to detect the subjects at risk for fractures, one should actively search for them, primarily in a group of postmenopausal women, considering clinical risk factors. Apart from others, the relevant risk factors are lack of estrogen and low body mass index (BMI <19 kg/m²).: The aim of this study was to examine relationship between body mass index (BMI) and bone mineral density (BMD) in a group of postmenopausal women.

Methods: The study involved a group of 100 postmenopausal women, aged 46 to 70 years. (59.08 ± 6.07). All subjects had their body mass and body height measured and BMI calculated. BMD was determined by DXA method (dual energy X-ray absorptiometry) by Lunar Prodigy Advance Unit. BMD was measured at central skeleton (lumbal spine and both hips). According to densitometry finding, the criterion for osteoporosis is T score less than –2.5 S.D. BMI values were correlated with total T score values of the lumbal spine and both hips, as well as total T score values of spine and hip.

Result: Results have shown that body mass was normal in 18% subjects, 1st grade obesity was found in 52%, 2nd grade obesity in 23%, 3rd grade obesity in 7% of subjects. Median BMI value was found in 28.27 ± 4.12. Median lumbal spine T score was – 2.19 S.D. ± 1.25, and hip T score – 1.11 S.D. ± 0.95. A statistically significant positive correlation (r = 0.01) was found between BMI and BMD of the hip, whereas between BMI and BMD of lumbal spine there was no statistically significant correlation. There was a statistically significant correlation (r = 0.01) between BMD values of lumbal spine and hip.

Conclusion: BMI is a well known, significant predictor of BMD of entire skeleton. In postmenopausal women BMI is more important predictor of hip BMD, as compared to spine BMD. BMD of hip is increased with the increase of body mass and height in postmenopausal women due to considerable endocrine function of fat tissue which produces leptin and other bioactive peptides which have a protective role in bone structure. A lack of correlation between BMI and BMD of spine in postmenopausal women might be due to predominant effect of lack of estrogen and faster bone metabolism in spinal region (spongious bone).