Physical Activity Associations with Bone Mineral Density and Modification by Metabolic Traits

The Effectiveness of Water- versus Land-Based Exercise on Specific Measures of Physical Fitness in Healthy Older Adults: An Integrative Review

As the population ages, maintaining an active lifestyle becomes increasingly vital to promote overall health and well-being in older individuals. Water- and land-based exercises have emerged as popular options, each offering a distinct set of benefits tailored to the unique needs of this population group. An electronic database search, including PubMed, Scopus, MEDLINE, and Web of Science, was conducted until 15 September 2023, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to investigate the effects of water-based compared to land-based exercise on selected fitness parameters in older healthy individuals. The eligibility criteria included studies with at least two groups of participants aged 60 and older, with physical fitness outcome measures. A total of ten studies met the inclusion criteria and were analyzed. While both exercise modalities may offer significant benefits, this review's findings emphasized the absence of conclusive evidence and consensus for recommending a single exercise category applicable to aquatic or land environments and providing more definite guidance to improve health-related physical fitness parameters in healthy older individuals. Finally, combining both training approaches may lead to a comprehensive array of health benefits for this age group population by also considering individual's needs, preferences, and fitness goals.

Association of Sun-Protective Behaviors With Bone Mineral Density and Osteoporotic Bone Fractures in US Adults

Importance

Despite the reassuring emerging evidence on the lack of a causal relationship between sun protection and vitamin D deficiency, there is scarce data on whether multimodal sun protection is associated with reduced bone mineral density (BMD) and/or increased prevalence of osteoporotic bone fractures. This lack of data may lead to worry and decreased sun-protective behaviors on the part of patients.

Objective

To investigate the association of sun-protective behaviors with BMD z scores and the prevalence of osteoporotic fractures.

Design, Setting, and Participants

This population-based cross-sectional study included data from US adults who participated in the 2017 to 2018 cycle of the National Health and Nutrition Examination Survey (NHANES). Data were analyzed between September and November 2020.

Main Outcomes and Measures

Definition of sun-protective behaviors (staying in the shade, wearing long sleeves, and sunscreen use), site-specific and total BMD, and osteoporotic fractures (hip, wrist, and spine) in the NHANES data.

Results

Data from 3418 adults 20 years and older (average age, 39.5 [95% CI, 38.6-40.4] years; 1612 [47.2%] men and 1806 [52.9%] women) who completed the NHANES dermatology questionnaire were included in this study. The prevalence of frequent staying in the shade, wearing of long sleeves, and sunscreen use were 31.6% (95% CI, 27.8%-35.7%), 11.8% (95% CI, 10.6%-13.1%), and 26.1% (95% CI, 23.5%-28.8%), respectively. The use of individual sun-protective behaviors was not associated with diminished site-specific and total BMD z scores in the multivariate models (estimate, -0.23 [95% CI, -0.47 to 0.02], P = .18; -0.08 [-0.27 to 0.12], P = .72; and -0.10 [-0.32 to 0.13], P = .15 for frequent staying in the shade, wearing of long sleeves, and sunscreen use, respectively). Moderate to frequent staying in the shade was associated with reduced prevalence of spine fractures in the multivariate model (odds ratio, 0.19 [95% CI, 0.04-0.86], P = 0.02).

Conclusion and Relevance

In this cross-sectional study, routine use of sun-protective behaviors among the US adult population was not associated with decreased BMD or increased risk of osteoporotic fracture. Sun protection may be associated with a modest decrease in the prevalence of osteoporotic fractures, possibly owing to risk-averse behaviors. These reassuring findings add to the growing body of evidence on the safety of sun protection, with no considerable negative association with bone health.