The Relation Between Calcaneus Stiffness Index as a Measure of Bone Density and Body Mass Index in an Egyptian Cohort

BACKGROUND: Obesity and osteoporosis are two conditions that are associated with morbidity and mortality; there is contradictory evidence regarding this association. PURPOSE: The aim of the current study was to explore further the association between obesity and calcaneus stiffness index (CSI), as a measure of bone density, in a community-based cross-sectional study in an Egyptian population. METHODS: A cross-sectional study was conducted among active subjects, aged ≥20 years old, over one year. CSI was measured by Quantitative ultrasound (QUS), in addition; QUS T-score and Z-score of the non-dominant heel scan were recorded. RESULTS: Two hundred and eighty participants were recruited; 7 subjects were excluded because of Z score more than −2, mean age was 61 (± 11.9) years, and mean BMI was 29.7 (±5.6). Female participants were 77.7%, with mean of age 60.3 (± 11.6); and age range 20–82 years. Male participants were 22.3%, with mean of age 63.6 (± 12.7); and age range 30–80 years. Older subjects (>55 years) had significantly lower CSI and worse T-score than the younger subjects (P < 0.001 for both). In the younger age group, BMI was not significantly associated with CSI, even after adjustment for gender (P= 0.52). However, in the older age group, BMI was significantly associated with stiffness index (P= 0.049, O.R.= 1.73), even after adjustment for gender (P= 0.041, O.R.= 1.7). CONCLUSION: Compared to young subjects, older subjects (≥55 years) had significantly lower bone strength as measured by CSI, and their BMI was significantly positively associated with bone density. In younger people (<55 years), BMI was not associated with bone strength.