Bone loss during menopausal transition among southern Chinese women

Estrogen deficiency during menopausal transition is associated with rapid bone loss. The purpose of this study was to examine the time of onset, the rate, and predictors of menopausal bone loss.

Prospective data were analyzed from 160 Chinese women between the ages of 45 to 55 years who participated in the Hong Kong Osteoporotic Study.

All participants were studied yearly for 4 years. Demographic information, menstrual status according to the Stages of Reproductive Aging Workshop (STRAW), and lifestyle habits were recorded as well as bone mineral density (BMD) measured every visit. Baseline follicular stimulating hormone, sex hormone binding globulin, parathyroid hormones, C-terminal telopeptides of type 1 collagen, estradiol and testosterone were also measured.

There was no significant bone loss at the spine, femoral neck and total hip in premenopausal women. Maximal bone loss occurred within the STRAW stage -2 and -1. Age at menopause, baseline age, body weight and FSH were independent predictors of bone loss. Subjects in the lowest quartile of baseline body weight (<50 kg) lost bone 2 times faster at spine compared with those in the highest quartile (>61 kg). Subjects in the highest quartile of baseline FSH (>40 IU/l) lost bone 1.3-2.3 times faster at all 3 sites compared with those in the lowest quartile (<5.8 IU/l).

Strategies to retard bone loss should be stressed to middle aged women, especially those with lean body built or with early menopause, to prevent osteoporosis later on in life.