Association between height loss and bone loss, cumulative incidence of vertebral fractures and future quality of life: the Miyama study

Introduction The study aimed to clarify associations between height loss, bone loss and the quality of life (QOL) score among general inhabitants of Miyama, a rural Japanese community. This population-based epidemiological study was conducted in Miyama, a village located in a mountain area in Wakayama Prefecture, Japan. Methods A list of all inhabitants comprising 1,543 inhabitants (716 men, 827 women) born in this village between 1910–1949 was compiled. From the above whole cohort, a subcohort to measure bone mineral density (BMD) was recruited, consisting of 400 participants, divided into four groups of 50 men and 50 women each, and stratified into age decades by decade of birth-year (1910–1919, 1920–1929, 1930–1939 or 1940–1949). BMD measurement, physical measurements of height (cm) and body weight (kg) were taken, and body mass index (BMI; kg/m²) were calculated. BMD and anthropometric measurements were repeated on the same participants at 3, 7 and 10 years after baseline measurement (1993, 1997 and 2000). Results and discussion Among 299 of 400 participants, changes in height over 10 years for men in their 40s, 50s, 60s and 70s were −0.7 cm, −0.5 cm, −1.2 cm and −1.5 cm, respectively, compared with −0.7 cm, −1.4 cm, −2.1 cm and −3.7 cm in women, respectively. No significant relationships between change in height and rate of change in BMD at the lumbar spine and femoral neck after adjustment for age in men (lumbar spine, β = 0.058, standard error of the mean (SE) = 0.031, P = 0.501, R² = 0.038; femoral neck, β = 0.100, SE = 0.038, P = 0.228, R² = 0.121) were identified. By contrast, among women, a significant positive association was identified between height change and change rate of BMD at the lumbar spine after adjusting for age (β = 0.221, SE = 0.039, P = 0.012, R² = 0.069), while no significant relationship was found between height change and change rate at the femoral neck (β = 0.107, SE = 0.039, P = 0.229, R² = 0.048). No significant relationship was noted between vertebral fractures (VFx) and height at baseline in men and women (men: odds ratio (OR) 0.93, 95% confidence interval (CI) 0.81–1.05, P = 0.24; women: OR 0.97, 95% CI 0.87–1.08, P = 0.58) or between VFx and height loss (men: OR 1.31, 95% CI 1.00–1.71, P = 0.051; women: OR 1.20, 95% CI 0.94–1.53, P = 0.14). In both men and women, no significant relationship was identified between utility of the EuroQol EQ5D questionnaire and height at baseline (men: β = −0.148, SE = 0.003, P = 0.202, R² = 0.076; women: β = 0.127, SE = 0.004, P = 0.235, R² = 0.048), and height change (men: β = −0.078, SE = 0.008, P = 0.452, R² = 0.065; women: β = 0.053, SE = 0.010, P = 0.608, R² = 0.038).