Strong familial association of bone mineral density between parents and offspring: KNHANES 2008-2011.

UNLABELLED: Bone mineral density (BMD) of offspring was significantly associated with their parents' BMD. Parental BMD Z-score ≤-1 was a significant predictor for BMD Z-score ≤-1 in their offspring. Peak bone mass acquisition during early adulthood is more substantially influenced by genetic factors rather than lifestyle or environmental factors.

INTRODUCTION

A person's BMD is affected by both genetic and environmental factors. Family history of osteoporosis or fragility fracture is a well-known risk factor for low bone mass or fracture. The purpose of the present study was to investigate the familial association of BMD between parents and offspring in Korean population.

METHODS

This is a cross-sectional study based on the data from the Korea National Health and Nutrition Examination Surveys (KNHANES) conducted from 2008 to 2011. A total of 5947 subjects (3135 parents and 2812 offspring) were included.

RESULTS

In age-adjusted partial correlation analyses, all BMD values acquired from the lumbar spine, femur neck, total hip, and whole body showed significant associations between parents and offspring. Among these associations, whole-body BMD showed the strongest relationship between offspring and parents. The narrow-sense heritability of BMD ranged from 0.203 to 0.542 in male offspring and from 0.396 to 0.689 in female offspring. Multiple linear regression analyses showed that offspring's BMD was independently associated with BMD of both parents after adjusting for covariates. Lifestyle or environmental factors including dietary calcium intake, serum 25-hydroxyvitamin D level, regular exercise, current smoking, and alcohol intake showed only moderate or no associations with BMD. In multiple logistic regression analyses in offspring aged 19-25 years, the son's risk of having BMD Z-score ≤-1 was associated with both parents' BMD Z-score ≤-1, while the daughter's risk was only associated with maternal BMD Z-score ≤-1.

CONCLUSIONS

Our findings confirm the strong familial association of BMD between parents and offspring in Korean population and suggest that peak bone mass acquisition during early adulthood is more substantially influenced by genetic factors rather than lifestyle or environmental factors.