Bone mineral density in the various regions of the skeleton in women with subclinical hypothyroidism: the effect of biological factors, bone turnover markers and physical activity

Study aim: This cross-sectional study examined the relationship between biological factors, physical activity (PA), bone turnover markers (BTMs) and bone mineral density (BMD) in women with subclinical hypothyroidism (SCH) and healthy.

Material and methods: The study included 135 women. Bone parameters were measured by the densitometry. Calcium, phosphorus, osteocalcin (OC), total alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BALP), vitamin D and cross-linked carboxyterminal telopeptide of type I collagen (ICTP) were measured in blood serum. PA were evaluated by metabolic equivalent of task (MET).

Results: Women with SCH had lower BMD in hip and lumbar spine, calcium, vitamin D and higher values of ICTP than the healthy group. In women with SCH, the affecting BMD in the femoral neck were ICTP (µg/l), (η² = 0.083), and also 25(OH)D (ng/ml), (η² = 0.080) and PA level (I/S), (η² = 0.115). BMD in the spine was affected by PA level (I/S), (η² = 0.173). The parameters affecting BMC in the femoral neck were 25(OH)D (ng/ml), (η² = 0.073). In all women sufficient levels of PA determined higher BMD.

Conclusions: PA and BTMs significantly determine BMD levels. PA can be an important area of rehabilitation and physical therapy as an available measure to counteract BMD loss in postmenopausal healthy women and those with SCH.