Diabetes diagnoses more prevalent among confirmed smokers
Confirmed smoking, especially in larger quantities and for longer durations, is associated with increased risk for diabetes, according to findings published in the Journal of Diabetes.
“This study showed that cotinine-verified current smoking, self-reported former and current smoking and unobserved smoking were all positively associated with higher [diabetes] prevalence in the overall population,” Byung Jin Kim, MD, PhD, of the division of cardiology in the department of medicine at Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea, and colleagues wrote. “Most cross-sectional studies revealed that cigarette smoking was positively associated with increased [diabetes] prevalence, which were consistent with the results in our study.”
Researchers assessed data from 145,040 adults (mean age, 37 years; 59% men) enrolled in the Kangbuk Samsung Health Study and Kangbuk Samsung Cohort Study between 2011 and 2013. Participants self-reported health data, including smoking status, and had urine cotinine levels measured. Researchers used both pieces of information to better estimate the population of smokers, and smoking status was verified with a urine cotinine level of more than 50 ng/mL.
Participants who were identified as smokers by the urine cotinine analysis (24.3% of the sample) had a diabetes prevalence of 4.4% (P .001), which was higher than both the prevalence in the total sample (2.7%; P .001) and in the group of verified nonsmokers (2.1%, P .001). Unobserved smokers — those not self-identified as smokers but with smoking confirmed by urine cotinine level — had a prevalence of 1.8%. Researchers found a 1.21-fold increase in diabetes prevalence for each 1 standard deviation increase in urinary cotinine level.
Similar results were found when using only self-reporting to determine smoking status. Diabetes prevalence among self-reported smokers was 4.5% (P .001) compared with 1.6% (P .001) among participants who said they had never smoked.
The quantity and duration of smoking also revealed a significant effect on diabetes prevalence: There was a 57% jump in prevalence for participants who smoked more than 20 cigarettes per day as well as a 28% increase for those who had been smoking for at least 10 years (P .01).
Researchers observed a much higher rate of verified smoking among men (38.5%) vs. women (3.8%), but sex did not play a significant role in determining diabetes prevalence.
The researchers noted that the study initially did not exclude participants with hepatic or renal disease, which could have affected urine cotinine results. However, a subsequent examination, which excluded the 2,754 participants with aspartate transaminase or alanine transaminase levels associated with such conditions, had similar results to the original study.
“This large cross-sectional study demonstrates that unobserved smoking as well as both cotinine-verified and self-reported smoking was associated with increased prevalence of [diabetes] compared to never smoking without any significant gender interactions,” the researchers wrote. “The present study suggests that self-reported questionnaires as well as validated biomarkers such as cotinine should be used together to more accurately evaluate actual smoking status and [diabetes] risk.” – by Phil Neuffer
Disclosures: The authors report no relevant financial disclosures.