Abstract
BACKGROUND: Physiological dysregulation (PD), quantified through the validated statistical method known as Mahalanobis distance (DM), reflects the progressive breakdown of homeostatic control across multiple, interdependent biological systems. Increasingly recognized as a fundamental hallmark of aging, PD is strongly associated with elevated risks of morbidity and mortality. Despite current knowledge on DM, it remains uncertain whether this metric is sensitive to lifestyle interventions. This gap limits the potential of DM as a responsive marker for monitoring changes in health status over time. OBJECTIVES: 1) To evaluate the impact of a 6-month caloric restriction (CR) program, either alone or in combination with structured exercise (CR + Ex), on PD. 2) To investigate whether changes in adipose tissue quantity and distribution mediate the effects of these interventions on PD. METHODS: Data from a total of 102 inactive overweight or obese postmenopausal women (CR: n = 68 vs CR + Ex: n = 34) were studied. Total adipose tissue and its distribution were measured using dual-energy X-ray absorptiometry and computed tomography scan. DM was calculated using 7 blood biomarkers: total cholesterol, HDL-C, LDL-C, triglycerides, C-reactive protein, albumin, and ferritin. RESULTS: After the interventions, there was a significant decrease in fat mass measurements and plasma level of ferritin (from 38.61 ± 4.60 to 36.35 ± 2.89 ng/mL), albumin (from 63.26 ± 51.08 to 56.43 ± 37.38 g/dL), and triglycerides (from 1.70 ± 0.77 to 1.48 ± 0.76 mmol/L) across the whole sample. However, PD increased for both group after the 6-month period. CONCLUSION: Despite improvements in specific biomarkers and reductions in fat mass, overall PD increased following the interventions. A non-significant trend toward attenuated dysregulation was observed in the combined CR and exercise group, but changes in adiposity did not significantly mediate this effect, suggesting that other biological mechanisms may underlie the systemic response.