Obesity and osteoporosis are two important and developing public health problems worldwide. Most studies to date on risk factors for osteoporosis have considered body mass index (BMI) only as a possible confounder. In this study, we assess the direct relationship between BMI and osteoporosis. Osteoporosis remains under-diagnosed, particularly in south Gujarat women, despite the availability of reliable diagnostic tests. In women, several screening tools, including heel ultrasound and clinical assessment tools, reliably predict low bone mass. The aim of this study was to determine relationship between body mass index (BMI) and Bone Mineral density (BMD) in healthy young women of south Gujarat. We conducted a cross-sectional study among women aged 25-60 years referred by their physicians for a bone mineral density (BMD) examination at health centre in South Gujarat between January 2016 and February 2016. BMI was determined prior to the BMD examination in the clinic. Information on other risk factors was obtained through a questionnaire. Bone mineral density (BMD) of the heel was measured by heel ultrasound. 273 women fulfilled the inclusion criteria for this study. BMI was inversely associated with BMD status. The population prevalence of osteopenia and osteoporosis were 72% and 67%, respectively. Using a heel ultrasound T score cut-off value of -1 or less, we predicted low bone mass (T-score of -2 or less at the heel). Women with low BMI are at increased risk of osteoporosis. To help reduce the risk of osteoporosis, patients should be advised to maintain a normal weight. The study demonstrated that numerous factors, both modifiable and non-modifiable, were significantly related to the prevalence of osteoporosis. The modifiable factors identified were participation in physical activity (three to five times per week) and body mass index (BMI). Non-modifiable factors included age. Low body-mass index, low calcium intake, current cigarette smoking, and physical inactivity were independent risk factors identified from population-based studies. The
presence of one or more risk factors was associated with having osteoporosis and low BMD in all groups. The strength of these associations was greater when two or more risk factors were present but varied with race/ethnicity, gender, and age. The prevalence of osteopenia and osteoporosis were unexpectedly high in women, who are considered to be at risk of high BMI. Heel ultrasound was able to predict low bone mass with sufficiently high sensitivity and specificity for use as a screening tool.
Key words: BMI, BMD, Osteoporosis