Causal relationship between obstructive sleep apnea and diabetic nephropathy: bidirectional and multivariable...

Area of Science:

• Nephrology
• Genetics
• Sleep Medicine

Background:

• Observational studies suggest a link between obstructive sleep apnea (OSA) and diabetic nephropathy (DN).
• The causal relationship and directionality between OSA and DN remain unclear.
• Mendelian randomization (MR) can help elucidate causal links using genetic variants.

Purpose of the Study:

• To investigate the causal effect of OSA on DN.
• To determine if DN causally affects OSA.
• To assess the independent effect of OSA on DN, adjusting for comorbidities.

Main Methods:

• Bidirectional two-sample Mendelian randomization (MR) analysis.
• Utilized large-scale genome-wide association study (GWAS) data for OSA and DN.
• Employed multiple MR methods (IVW, MR-Egger, weighted median) and sensitivity analyses.

Main Results:

• OSA was found to have a significant causal effect on increasing DN risk (IVW OR=1.41, p=0.003; Weighted Median OR=1.57, p=0.003).
• No evidence of a causal effect of DN on OSA was observed.
• Multivariable MR confirmed OSA's independent causal influence on DN, even after adjusting for hyperlipidemia and hypertension (OR=0.90, p=0.021).

Conclusions:

• Obstructive sleep apnea is a causal risk factor for diabetic nephropathy.
• Diabetic nephropathy does not appear to causally influence obstructive sleep apnea.
• OSA may contribute to diabetic nephropathy pathogenesis through mechanisms independent of common metabolic risk factors.