Blood pressure and calcium intake are related to bone density in adult males

Based on the premise that elevated blood pressure and low bone mass have bo th been associated with poor Ca nutriture and disturbances in Ca metabolism , a cross-sectional study was employed to determine if blood pressure and d ietary Ca intake were significantly related to bone mass. Forty-seven men b etween 24-77 years of age with blood pressure values ranging from normal to mildly elevated comprised the study group. Blood pressure was measured wit h a random-zero sphygmomanometer. Bone mineral content (BMC) and density (B MD) of the hip, spine and total body were measured with dual-photon absorpt iometry. Dietary intake and physical activity were also assessed. Multiple linear regression analysis was used for statistical analysis. After adjusti ng for known confounding variables (age, BMI, Ca intake, and others) diasto lic blood pressure was negatively related to BMC (P less than or equal to 0 .05) and BMD (P less than or equal to 0.01) of the total body, trochanteric region (P < 0.01) and Ward's triangle (P < 0.05), and to BMC of the femora l neck (P < 0.05) and lumbar spine, although the latter was just shy of sta tistical significance (P = 0.058). Systolic blood pressure was negatively r elated to trochanteric BMD (P = 0.04) and BMC (P = 0.06). Ca intake was pos itively related to total body BMD (P = 0.005), and BMC of the lumbar spine (P = 0.05). In this population of men, Ca intake was a positive predictor, and blood pressure was a negative predictor of regional measures of bone ma ss. These findings support the concept that independent of age, BMI and Ca intake, elevated blood pressure varies indirectly with bone mass and densit y, known predictors of osteoporotic fractures. Future studies are needed to determine whether elevated blood pressure is causally related to the devel opment of low bone mass, and what role dietary Ca plays in that pathway.