Waist Circumference: A Key Determinant of Bone Mass in University Students

This study aimed to assess bone mineral density (BMD) status, and to explore association between lifestyle behaviors, body mass index (BMI), waist circumference (WC) and BMD status of 217 students (55 males and 162 females) aged between 17 - 23 years studying at Walailak University. The BMD was measured at distal-third radius, and confirmed at mid-shaft tibia by Quantitative ultrasound analysis. BMI and WC were recorded to assess obesity, and lifestyle behaviors were evaluated using a questionnaire. Results showed 10.9 % males and 16 % females had low BMD (Z-score < -1) at both sites, while 29.1 % males and 11.8 % females were classified in the risk group. Proportions of the obese subjects assessed by BMI and WC were found to be greater in males (10.9 and 21.8 %) than females (6.8 and 18.5 %). Lifestyle behaviors of both genders were not much different. Only 45.2 % consumed milk ³ 3 packs/week. Most subjects (87.1 %) consumed high cholesterol diets (³ 3 days/week), while 24 % did exercise ³ 3 times/week. Both factors are of concern for the obese group. Crude analysis showed BMI, WC and milk intake are potential determinants of BMD. Final analysis indicated students with normal WC are found greater in a high BMD group than in a normal BMD group (RRR = 4.38), and the expected risk in the BMD group is lower for female students (RRR = 0.37). We suggest that to prevent osteoporosis in later life, healthy lifestyle practices should be promoted and obesity must be careful monitored during the age of peak bone mass.