Metabolic syndrome, type 2 diabetes affect lung capacity
Adults with metabolic syndrome or type 2 diabetes are more likely to have lower lung capacity measurements, according to research in Clinical Endocrinology.
In a joint analysis between Chinese and Australian populations to assess the relationship between lung capacity measurements and metabolic disorders, researchers found that a forced expiratory volume in 1 second (FEV1) of less than 2.7 L was associated with a high risk for metabolic syndrome and type 2 diabetes.
“The risk for type 2 diabetes and [metabolic syndrome] decreased over the 1.76 to 2.70 L range of FEV1, but neither increased nor decreased below 1.76 L or above 2.70 L,” Dahai Yu, PhD, of the department of nephrology at the First Affiliated Hospital, Zhengzhou University, China, and colleagues wrote. “This was remarkably consistent in these two independent samples from two different countries.”
Yu and colleagues analyzed data from 1,454 adults in Victoria, Australia (the Crossroads study), and 5,824 adults in Nanjing, China (the Nanjing Community Cardiovascular Risk survey), from randomly selected households. Participants completed questionnaires to provide medical history and completed an oral glucose tolerance test and spirometric measurements; researchers measured blood pressure, body weight, height and lipid profile. Researchers used logistic regression to calculate adjusted ORs for metabolic syndrome and type 2 diabetes with lung capacity measurements; dose-response relationships were explored using restricted cubic spline models.
Within the Crossroads cohorts, 28.9% of participants had metabolic syndrome; 9.4% had type 2 diabetes. Within the Nanjing cohort, 24.1% had metabolic syndrome; 8.1% had type 2 diabetes. Researchers found that, among Chinese participants, the mean FEV1 was 2.42 L for those without metabolic syndrome or diabetes vs. 2.12 L and 2.15 L for those with metabolic syndrome and type 2 diabetes, respectively. Among Australian participants, the mean FEV1 was 2.95 L for those without metabolic syndrome or diabetes vs. 2.73 L and 2.35 L for those with metabolic syndrome and type 2 diabetes, respectively.
Researchers found a nonlinear relationship between FEV1 and the risk for type 2 diabetes and metabolic syndrome in both populations (P < .0001 for both). The FEV1 associated with the lowest risk for type 2 diabetes and metabolic syndrome was more than 2.7 L (95% CI, 2.68-2.72 for Chinese participants; 95% CI, 2.65-2.76 for Australian participants).
“Significant reverse associations were identified between lung capacity measurements (both FEV1 and [forced vital capacity]) and both fasting glucose and lipids in the Chinese and Australian general populations,” the researchers wrote.
“We focused our investigation on the shape of the relationship, assessing the evidence for non-linearity and, in particular, on the existence of a threshold,” the researchers wrote. “In our analyses, we found consistent evidence that the associations are non-linear between FEV1 and metabolic disorders (both type 2 diabetes and [metabolic syndrome]).” – by Regina Schaffer
Disclosure: The researchers report no relevant financial disclosures.