Studies have found that lower peak bone mineral density (BMD) in youth may be the single most important factor leading to the development of osteoporosis at a later age.1-3 Despite the importance of this measurement, the actual age at which peak BMD is reached and factors affecting age at peak BMD are thus far undetermined. A cross-sectional study published in Bone found that the age at attainment of peak BMD varies by sex and skeletal site.4
Cross-sectional data from a total of 18,713 individuals in the 2005 to 2014 United States National Health and Nutrition Examination Survey (NHANES) database were used to calculate the average age at attainment of peak BMD at the femoral neck, total hip, and lumbar spine. Only individuals with complete and valid data on BMD in the NHANES database were considered for the study. The correlation of age at attainment with sex, skeletal site, race, and body mass index were examined.
Dual-energy x-ray absorptiometry (DXA) was used to measure BMD. Femur and spine scans acquired from 2005 to 2010 were obtained using either the Hologic QDR-4500A densitometer or the Hologic Discovery® A densitometer. Femur scans acquired from 2005 to 2010 were analyzed with Hologic Discovery v12.4, spine scans acquired from 2005 to 2010 were analyzed with APEX v3.0, and femur and spine scans acquired in 2013 and 2014 were analyzed with APEX v4.0 software. Although various DXA machine models and software were used, a previous study determined there was no significant difference between mean BMD analyzed by Hologic Discovery v12.4 and APEX v4.0.5 Various quality control efforts were undertaken throughout this study to ensure data quality.6
The average age of individuals in the study was 36.0±21.1 years for men and 40.0±21.2 years for women, with approximately equal representation from men and women (51.1% and 48.9%, respectively). The average age at peak femoral neck, total hip, and lumbar spine BMD was 20.5, 21.2, and 23.6 years, respectively, in men and 18.7, 19.0, and 20.1 years, in women, respectively.
This study found that the age at peak BMD varied by sex and skeletal site, with men attaining peak BMD later than women at all sites (P <.001). The average age at peak attainment for both men and women was earliest at the femoral neck, followed by total hip, and latest at the lumbar spine. Race and body mass index were not associated with age at attainment of peak BMD (all P >.05).
A limitation in this study was the use of cross-sectional data instead of longitudinal data to estimate age at attainment of peak BMD and related factors, although longitudinal data are generally not available for these measures.
“These results suggested that improving bone health among individuals before 20 years [of age] may be useful for reducing future risk of osteoporosis and osteoporotic fractures,” concluded the researchers.
1. Teegarden D, Proulx WR, Martin BR, et al. Peak bone mass in young women. J Bone Miner Res. 1995;10(5):711-715.
2. Lin YC, Lyle RM, Weaver CM, et al. Peak spine and femoral neck bone mass in young women. Bone. 2003;32(5):546-553.
3. Hernandez CJ, Beaupre GS, Carter DR. A theoretical analysis of the relative influences of peak BMD, age-related bone loss and menopause on the development of osteoporosis. Osteoporos Int. 2003;14(10):843-847.
4. Xue S, Kemal O, Lu M, Lix LM, Leslie WD, Yang S. Age at attainment of peak bone mineral density and its associated factors: the National Health and Nutrition Examination Survey 2005–2014. Bone. 2020;131:115163.
5. Looker AC, Sarafrazi Isfahani N, Fan B, Sheperd JA. Trends in osteoporosis and low bone mass in older US adults, 2005-2006 through 2013-2014. Osteoporos Int. 2017;28(6):1979-1988.
6. Wahner HW, Looker A, Dunn WL, Walters LC, Hauser MF, Novak C. Quality control of bone densitometry in a national health survey (NHANES III) using three mobile examination centers. J Bone Miner Res. 1994;9(6):951-960.