Dr. Karam Al Jumaily's team at Yale University analyzed over a million U.S. military veterans and found something that could reshape how clinicians approach diabetes prevention: veterans with both insomnia and obstructive sleep apnea face a diabetes risk more than six times higher than those without either condition. The discovery matters profoundly because sleep disorders—particularly when they occur together—may represent a largely overlooked pathway to type 2 diabetes, one that persists even after accounting for weight, smoking, blood pressure, and psychiatric health.
The research, presented at the SLEEP 2026 annual meeting in Baltimore and published in the journal Sleep, analyzed 1,074,113 veterans (mean age 33 years, 12% women) who were free of sleep disorders and type 2 diabetes at enrollment. Researchers tracked participants through the Department of Veterans Affairs system using standardized disease codes and laboratory findings to identify new diabetes cases. The numbers tell a stark story of risk escalation: insomnia alone raised diabetes risk by 41%, with women facing a 48% increase and men a 39% increase. Obstructive sleep apnea alone was more dramatic—over five times higher risk in men and nearly four times higher in women. But the combination, known as COMISA (comorbid insomnia and sleep apnea), proved most dangerous: a 6.2-fold increased risk overall, climbing to 6.5 times higher in men and 4.7 times higher in women.
What struck Al Jumaily most was the persistence of these associations. Even after adjusting for a sweeping range of known diabetes risk factors—demographic characteristics, body mass index, smoking status, hypertension, high cholesterol, psychiatric conditions, and substance use—the link between sleep disorder combinations and diabetes remained significant. This suggests that sleep disorders themselves, independent of other metabolic or behavioral factors, are driving excess risk. "These associations remained significant even after accounting for a broad range of demographic, metabolic, psychiatric, and behavioral risk factors," Al Jumaily said. "This suggests that sleep disorders may represent an independent and under recognized risk factor for future cardiometabolic disease."
The findings carry particular weight in veteran populations, where both sleep disorders and metabolic disease overlap frequently. Many veterans experience sleep disruptions linked to service-related conditions, making them uniquely vulnerable to this compounding risk. The American Academy of Sleep Medicine notes that insomnia and obstructive sleep apnea are among the most common sleep disorders in the United States, each independently tied to serious health problems. Yet the study reveals that their combination creates risk that far exceeds what either disorder alone would predict.
Al Jumaily emphasized that the results point toward early intervention as a practical prevention strategy. Screening for sleep disorders—not just weight, smoking, or cholesterol—should become a standard part of diabetes risk assessment, especially in younger populations where the risk appears particularly elevated. "COMISA represents an important sleep phenotype that clinicians and public health practitioners should be aware of, especially in veteran populations," he noted. For the millions of Americans experiencing insomnia or sleep apnea, the message is clear: seeking evaluation from a sleep medicine specialist isn't just about better rest. It may be one of the most direct paths to preventing type 2 diabetes.