Total body bone area, bone mineral content, and bone mineral density for individuals aged 8 years and over: United States, 1999-2006.

Abstract

Objectives: This report presents bone measurement data from total body dual energy x-ray absorptiometry scans for 28,454 persons aged 8 years and over who participated in the 1999-2006 National Health and Nutrition Examination Survey. The sample consisted of 22,667 respondents with valid data, and 5,787 with missing data that were successfully multiply imputed (i.e., not highly variable). Bone area, bone mineral content, and bone mineral density (BMD) are presented for the total body, the total body minus the head (e.g., subtotal), and 10 subregions of the body.

Methods: Means, standard deviations, and selected percentiles were calculated for the total body, total body minus head (subtotal), and 10 body subregions by sex, race and ethnicity, and age. Smoothed mean total body BMD was plotted by age, sex, and race and ethnicity. Multiple regression was used to evaluate differences in mean total body BMD by age, sex, and race and ethnicity.

Results: After adjusting for race and ethnicity, total body BMD among those under age 20 was significantly higher in respondents aged 12-19 than in those aged 8-11 in both sexes. Among adults of both sexes, total body BMD in persons aged 20-49 was significantly higher than in those aged 50-79, and significantly lower in persons aged 80 and over than in those aged 50-79, after adjusting for race and ethnicity. After adjusting for age, total body BMD was significantly higher in non-Hispanic black persons than in non-Hispanic white persons, regardless of age or sex. However, the pattern differed by age when Mexican-American persons were compared with non-Hispanic white persons: Age-adjusted total body BMD was significantly lower among Mexican-American males aged 8-19, was similar in Mexican-American females aged 8-19, and was significantly lower in Mexican-American men and women aged 20 and over.