The influence of lifestyle, menstrual function and oral contraceptive use on bone mass and size in female military cadets

Abstract

PurposeTo determine the influence of menstrual irregularity, oral contraceptive use and other factors on bone mineral density (BMD) and bone size at different skeletal sites in 135 college-aged fit women.MethodsMenstrual history, oral contraceptive use, exercise history, and nutritional factors including calcium, caffeine, and alcohol intake as well as tobacco use were determined by written survey. Height, weight and fitness levels were measured. Spine and hip BMD were measured by dual x-ray absorptiometry (DXA), calcaneus BMD by peripheral DXA, and tibial bone mineral content (BMC) and size by peripheral Quantitative Computed Tomography (pQCT).ResultsThe mean age was 18.4 ± 0.8 years. Weight and prior exercise were positively related to BMD at most skeletal sites and to tibial bone size. Milk intake was positively related to calcaneal BMD, tibial BMC and cortical thickness. Fracture history was an important predictor of spine, hip and heel BMD. Women who had ≥ 10 menstrual cycles in the year prior to BMD measurement had higher BMD at all sites as well as a greater tibial mineral content and cortical thickness than women who had oligomenorrhea/amenorrhea (≤ 9 cycles in the prior year; all p < 0.05). Oral Contraceptive (OC) users had significantly lower BMD in the spine (p < 0.02) and calcaneus (p = 0.04), smaller tibial periosteal circumference and lower tibial mineral content (p < 0.02) than non-OC users.ConclusionIn a population of fit, college-aged women, OC use and oligomenorrhea were associated with reduced BMD and bone size. Weight, as well as prior exercise and milk intake was positively related to bone density and size at some skeletal sites. Understanding these relationships would help improve skeletal health in young women.

Steroidal contraceptive use is associated with lower bone mineral density in polycystic ovary syndrome

“…This is in contrast to positive associations with dairy or calcium intake with BMD in pre-menopausal women [16] and reduced osteoporosis or fracture risk in pre-or post-menopausal women [17] and positive effects of dairy on BMD in pre-menopausal women using steroidal contraceptives [18]. In this prior study, women consumed a calcium deficient diet on study commencement (\800 mg/day) [18] in contrast to the higher levels (*1000 mg/day) reported here.…”

Oral contraceptive use and bone mass in women aged 26–36 years

“…Previous cross-sectional studies examining the association between OC use and BMD in samples of young women (≤25 years) have had conflicting results with findings of no association in relatively small samples [11,12] or a negative associations in samples recruited from a university setting or from fit, heavily exercising female military cadets [2,3]. Our study findings contrast with these studies but are consistent with other reports on the associations between combined oral contraceptive use and BMD.…”

“…Current combined OC use in peri-menopausal and postmenopausal women (e.g., in randomized trials) was positively associated with BMD, but was not different between former OC users and never users in this older group [1]. More recently, several studies have examined the associations in young women and also presented inconclusive results [2][3][4][5], with negative associations in samples recruited from a university or from fit, heavily exercising female military cadets [2,3], and a beneficial effect in female athletes over 2 years follow-up [4]. Progesterone only contraceptives, such as depot medroxyprogesterone acetate (DMPA), have been associated with lower BMD in young women [6] but studies of other types of progestogen-only contraceptives and BMD are limited [7].…”

Premenopausal Women with a Distal Radial Fracture Have Deteriorated Trabecular Bone Density and Morphology Compared with Controls without a Fracture

“…A similar association between low bone mineral density and traumatic fracture risk in older men and women has been previously reported 36 . Potential reasons for low bone mineral density in our patient population include genetic factors 37,38 , menstrual function [39][40][41] , oral contraceptive use 42 , poor dietary intake 43,44 , and lower physical activity [45][46][47] . Of these, late menarche and lower physical activity 39,45,48,49 lead to a deterioration of bone microarchitecture as measured by HR-pQCT.…”