Is the LEPR rs1137101 GG genotype associated with adiposity and weaker sleep-related respiratory compensation?

At age 57, this genetic finding should be interpreted as a modest risk modifier rather than a diagnosis or explanation for sleep-related breathing symptoms. The strongest evidence separates an obesity-susceptibility association from an unproven GG-specific defect in leptin signaling.

Genetic and adiposity evidence

• LEPR rs1137101 GG (Q223R Arg/Arg) was associated with obesity in a 2024 meta-analysis of 39 case-control studies (6,099 cases; 6,711 controls): OR 1.39 versus AA (95% CI 1.12–1.73).
• The association was heterogeneous (I²=63%), stronger in Asian populations and not statistically significant in Caucasian populations. Earlier pooled evidence was null overall (OR 1.05, 95% CI 0.92–1.21).
• Thus, GG may modestly increase susceptibility to adiposity in some populations, but it is not determinative and does not establish an independent association with obstructive sleep apnea.

Leptin-resistance interpretation

• Q223R alters the extracellular LEPR domain, creating a biologically plausible hypothesis of altered receptor behavior.
• Direct functional studies found no meaningful differences in leptin-induced STAT3 signaling or transcription, and humanized mice showed no differences in adiposity, energy expenditure, or metabolic response. A GG-specific predisposition to leptin resistance therefore remains uncertain.

Respiratory mechanisms

• Impaired leptin signaling can weaken compensatory sleep ventilation, especially the hypercapnic (CO₂-driven) response. Leptin-deficient mice have lower sleep ventilation and markedly blunted CO₂ responsiveness; leptin replacement restores these effects independent of weight.
• Leptin deficiency/resistance also promotes sleep-related hypoventilation and pharyngeal collapsibility in animal models. Relevant pathways include hypothalamic, medullary/retrotrapezoid, carotid-body, and respiratory motor-control circuits.
• In 186 humans, higher leptin correlated independently with lower hypercapnic drive, but this does not prove causation because leptin strongly tracks adiposity and sleep apnea-related mechanics.

Bottom line

• GG plausibly contributes to adiposity susceptibility, but not established leptin resistance. Impaired leptin signaling has a supported mechanistic role in reduced CO₂-compensatory breathing during sleep; whether this genotype causes that impairment in an individual remains unproven.