Obesity Linked to Decreased Lung Function in Metabolic Syndrome and Diabetes
In a recent study, US researchers investigated whether reduced lung function is linked to metabolic syndrome (MS) and diabetes mellitus (DM) in American Indians (AIs). They also looked at whether decreased lung function is present before or after the development of MS or DM.
Results appeared in the October 2011 issue of Diabetes Care in the article “Obesity in adults is associated with reduced lung function in metabolic syndrome and diabetes: the Strong Heart Study.”
The Strong Heart Study (SHS)—a multi-center, prospective study—analyzed cardiovascular disease (CVD) and its associated risk factors in AI adults.
Researchers used lung function assessment by standard spirometry at the SHS second examination (1993 to 1995) in 2,396 adults with or without MS or DM. Study participants did not have lung disease or CVD.
For those participants who did not have MS or DM, the development of MS/DM at the SHS third examination (1996 to 1999) was examined.
Did Researchers Find a Link Between Reduced Lung Function and Diabetes?
The research team observed that AIs with MS or DM had considerably lower lung function. Reduced lung function was linked to MS and DM after adjustment for:
- abdominal obesity
- current smoking status
- physical activity index
- SHS field center
The investigators also noted that forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were not associated with insulin resistance or severity of DM, nor were they associated with serum markers of inflammation (p<0.05).
The FVC and FEV1-to-FVC ratio both predicted DM in unadjusted analyses but not when they were adjusted for co-variates, including waist circumference. However, in the adjusted model, abdominal obesity predicted MS and DM.
The study found that decreased lung function is independently linked to MS and DM, and reduced lung function is present before developing MS or DM, possibly due to the impact of obesity and inflammation.