Daily step recommendation adherence and peak bone mineral density among female nurses: A cross-sectional study

This study aims to investigate the effects of popular 6000/10,000 daily step recommendations of physical activity on bone mass in young female nurses. A sample of 69 female nurses aged 22 to 35 from a teaching hospital in Chongqing, China, were invited to participate in the study. Daily walking steps were recorded by a smartphone-based application for 30 consecutive days. The participants were divided into 3 groups based on their adherence to daily step recommendations: low (average daily steps < 6000), moderate (6000 ≤ average daily steps ≤ 10,000 steps), and high (average daily steps > 10,000 steps) steps. Bone mineral density (BMD) at multiple sites (spine, hip, and heel) was measured with dual-emission X-ray scanner. Analysis of variance was used to compare BMDs in different level of daily steps, multivariable regression analysis was used to adjust the confounders. Nurses with adherence to higher step recommendation had higher means of BMDs at all bone sites, but only BMDs at spine (L1-L4, all P < .05) were significant. Multivariate regression analysis showed the nurses with moderate to high steps had significantly higher BMDs at the spine (P ≤ .001 for L1-L4) and hip (Ward triangle P = .047, trochanteric region P = .025, and intertrochanteric region P = .019) than those with low steps after controlling for potential confounders. However, there was no significant relationship between daily step recommendation adherence and BMD at the femoral neck (P = .092) or the heel (calcaneus P = .367). Adhere to the recommendation of 6000/10,000 steps per day without considering types of physical activity increases the bone mass in bones of spine and hip in young females.The 6000/10,000 steps daily can be recommended as a brief goal of physical activity for the prevention of osteoporosis.Cohort studies with big sample size, and diverse population are warranted to further confirm the effect of step goals on bone health.