A review of 50 longitudinal papers found insulin-related signals lined up with adverse muscle and fat changes in adults 50 and older

What the research found

Emeline Michel and colleagues published a narrative review in GeroScience on 4 November 2026. They looked for longitudinal human studies that tied biomarkers from the hallmarks-of-aging framework to changes in body composition. Eligible studies enrolled adults aged 50 and older and measured body composition more than once, mostly with dual-energy X-ray absorptiometry. They found 50 articles: 3 on primary hallmarks, 20 on antagonistic hallmarks, and 24 on integrative hallmarks. Chronic inflammation was the most studied hallmark. They found no study for genomic instability, epigenetic alterations, proteostasis, macroautophagy, cellular senescence, stem cell exhaustion, or dysbiosis. Telomere length was the only primary hallmark in the set, and it had no consistent link with body-composition change. For nutrient sensing, insulin resistance, hyperinsulinemia, and impaired glucose handling lined up with adverse muscle and fat changes. Mitochondrial evidence used indirect markers and fit adiposity more than muscle or bone. Hormone markers, trace elements, and inflammatory indices varied by marker, sex, and tissue compartment. The authors call the evidence limited and uneven. This is a review of existing studies. DOI 10.1007/s11357-026-02629-6. Not medical advice.

Evidence level: Human study. A study in people, but an association isn't proof of cause.

Read the original at GeroScience