Body Composition Affects POAG Risk, Study Finds

A large study involving nearly 300,000 healthy adults found a consistent link between greater leg fat mass and lower POAG risk, while arm fat conferred additional protection in older adults. While further research is needed to elucidate the mechanisms behind these associations, overall, these findings support the hypothesis that maintaining a healthy body composition pattern may mitigate POAG risk. Photo: Justin Cole, OD, and Jarett Mazzarella, OD. Click image to enlarge. Previous research has suggested a possible, albeit inconsistent, link between increased body mass index (BMI) and the risk of primary open-angle glaucoma (POAG). However, this says little about the influence of body composition on disease risk, since BMI fails to differentiate between fat and lean mass, nor does it consider the distribution of these components within the body. In a new cross-sectional and cohort study, researchers investigated whether POAG risk differs based on body composition, concluding that the two appear to have a complex relationship with age-dependent effects. Their findings, described below, were published recently in American Journal of Ophthalmology.Conducted on a large scale using data from the UK Biobank, the study encompassed a diverse cohort of 88,123 participants for baseline intraocular pressure (IOP) analysis and 291,983 for examining POAG incidence. Participants included healthy adults aged 40 and above. The researchers employed bioimpedance analysis to estimate fat and muscle mass in various body regions: arms, trunk and legs. Numerous covariates were considered in the analysis, such as age, sex, ethnicity, socioeconomic status, lifestyle habits and history of hypertension and diabetes.The results showed that participants with greater leg fat had a significantly reduced risk of developing POAG, with a hazard ratio (HR) of 0.85. Conversely, higher arm and trunk fat were correlated with increased IOP levels, signifying a potential risk factor for glaucoma. These associations varied by age; for example, when focusing specifically on older adults, greater arm and trunk fat offered some protective benefits against POAG.While no associations were observed between muscle mass and POAG incidence, the researchers did find that greater leg and trunk muscle mass was associated with lower IOP. This finding was consistent with prior investigations that suggest muscle mass exerts an IOP-lowering effect, while fat may contribute to higher IOP.As the authors explained in their AJO paper, “The associations between fat mass and the risk of POAG that vary by [anatomical] region are plausible, considering that different areas have varying amounts of fat with significantly different metabolic and inflammatory roles.” In epidemiological studies, for example, greater leg fat mass has been independently associated with a healthier lipid and glucose profile, translating to a reduced cardiovascular and metabolic risk. “Given that the risk of POAG is closely associated with metabolic health,” the researchers elaborated, “leg fat accumulation may represent a healthier metabolic phenotype, thereby effectively reducing the risk of POAG.”Regarding the protective effect of arm fat against POAG in older adults observed in this study, the authors explained that peripheral fat loss is a common phenomenon associated with aging, often linked to impairments in adipogenesis and heightened inflammatory processes. Therefore, “higher arm fat storage may represent a state of lower inflammation and better metabolic status,” they surmised. The protective function of trunk fat in older adults is more of an enigma that necessitates further investigation, they noted.In conclusion, the researchers wrote, “Maintaining a healthy fat distribution pattern could potentially confer benefits for both metabolic health and a reduced risk of POAG. Further research is warranted to clarify the underlying mechanisms and to inform targeted prevention and treatment strategies.”Click here for the journal source. Chen J, Xiao Y, Chen X, et al. Association between body composition and risk of primary open-angle glaucoma. Am J Ophthalmol. December 19, 2025. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.