Bone Mineral Density Changes during the Menopause Transition in a Multiethnic Cohort of Women

TLDR

Bone loss during the menopause transition is poorly understood, with limited knowledge of rates and influencing factors. The study aimed to quantify bone loss rates at each transition stage and identify major modifying factors. A longitudinal cohort of 1,902 African‑American, Caucasian, Chinese, and Japanese women was followed for up to six annual visits, during which lumbar spine and total hip BMD were measured. BMD remained stable in pre‑ and early perimenopause but declined markedly in late perimenopause (0.018 g/cm² yr at the spine, 0.010 g/cm² yr at the hip) and continued to fall at similar rates in early postmenopause (0.022 g/cm² yr spine, 0.013 g/cm² yr hip); bone loss was 35–55 % slower in women with higher body weight, and ethnicity had no independent effect, underscoring body weight as the key determinant and suggesting clinicians consider screening timing accordingly.

Abstract

Rates of bone loss across the menopause transition and factors associated with variation in menopausal bone loss are poorly understood.Our objective was to assess rates of bone loss at each stage of the transition and examine major factors that modify those rates.We conducted a longitudinal cohort study of 1902 African-American, Caucasian, Chinese, or Japanese women participating in The Study of Women's Health Across the Nation. Women were pre- or early perimenopausal at baseline.We assessed bone mineral density (BMD) of the lumbar spine and total hip across a maximum of six annual visits.There was little change in BMD during the pre- or early perimenopause. BMD declined substantially in the late perimenopause, with an average loss of 0.018 and 0.010 g/cm2.yr from the spine and hip, respectively (P<0.001 for both). In the postmenopause, rates of loss from the spine and hip were 0.022 and 0.013 g/cm2.yr, respectively (P<0.001 for both). During the late peri- and postmenopause, bone loss was approximately 35-55% slower in women in the top vs. the bottom tertile of body weight. Apparent ethnic differences in rates of spine bone loss were largely explained by differences in body weight.Bone loss accelerates substantially in the late perimenopause and continues at a similar pace in the first postmenopausal years. Body weight is a major determinant of the rate of menopausal BMD loss, whereas ethnicity, per se, is not. Healthcare providers should consider this information when deciding when to screen women for osteoporosis.