Circadian Rhythm Disruption, Sleep Disorders, and Their Role in Obesity‑Linked Diabetes
Abner Tom Kalukusu
Department of Clinical Medicine and Dentistry Kampala International University Uganda
Email: abnertomkalukusu@studwc.kiu.ac.ug
ABSTRACT
Circadian timekeeping aligns cellular metabolism with daily cycles of light, feeding, and activity. In obesity‑linked type 2 diabetes (T2D), misalignment between endogenous clocks and behavior via shift work, social jetlag, evening eating, short/fragmented sleep, insomnia, or sleep-disordered breathing exacerbates insulin resistance (IR), impairs β-cell function, and worsens glycemic variability. Molecular clocks (CLOCK, BMAL1, PER, CRY) coordinate transcriptional oscillations in liver, skeletal muscle, adipose tissue, pancreas, and gut; disruption alters glucose production, lipid handling, adipokine release, mitochondrial quality control, and inflammatory tone. Acute sleep restriction reduces insulin sensitivity within days through sympathetic and HPA‑axis activation, increased evening cortisol, GH, and catecholamine shifts, and elevated free fatty acids; chronic restriction sustains ectopic fat and endothelial dysfunction. Obstructive sleep apnea (OSA) adds intermittent hypoxia and arousal-driven surges in sympathetic activity, raising nocturnal glucose and blood pressure and aggravating NAFLD. Meal timing interacts with clocks: late eating increases postprandial glycemia and decreases diet-induced thermogenesis; early time-restricted eating improves fasting glucose and HOMA‑IR independent of large weight loss. Interventions: sleep hygiene, cognitive behavioral therapy for insomnia (CBT‑I), positive airway pressure for OSA, light management, melatonin timing in circadian disorders, exercise timing, and chrononutrition restore alignment and augment pharmacotherapy (GLP-1 receptor agonists, SGLT2 inhibitors, TZDs) and surgery when indicated. Precision strategies combine chronotype, actigraphy/polysomnography, continuous glucose monitoring (CGM), and metabolomics to tailor timing prescriptions and medication dosing. This review synthesizes mechanisms linking circadian/sleep disruption to diabesity, evaluates disease-specific sleep disorders, and outlines pragmatic, scalable, and equitable chronobiology-informed care.
Keywords: circadian rhythm; sleep disorders; insulin resistance; time‑restricted eating; type 2 diabetes
CITE AS: Abner Tom Kalukusu (2026). Circadian Rhythm Disruption, Sleep Disorders, and Their Role in Obesity Linked Diabetes. IAA Journal of Applied Sciences 14(1):72-78.