The cardiovascular, neuropathic, renal, and retinal consequences of diabetes are well known, but another organ system may soon be added to that list: respiratory. A recent literature review suggests that people with diabetes have impaired lung function similar to the impairment seen in smokers.

Pulmonary function data from 40 studies involving 3,182 people with diabetes and 27,080 control subjects demonstrated that in the absence of overt pulmonary disease, “Diabetes is associated with a modest, albeit statistically significant, impaired pulmonary function in a restrictive pattern” (Chest. 2010:138:393-406). The results stood regardless of BMI, smoking, diabetes duration, or hemoglobin A1c levels and applied to both type 1 and type 2 diabetes.

One possible explanation for the impairment is that diabetes-related microvascular damage may reside in the lungs in parallel to complications seen in the nerves, kidneys, and retinas. Another possibility is that the collagen- and elastin-rich thorax and lungs are prone to stiffening as a result of glycation.

“Because of the reasonable doubts that the decline in pulmonary function is actually caused by diabetes, it remains unclear whether tighter glycemic control would be beneficial for the pulmonary function,” acknowledged the authors. However, “considering the rapidly increasing prevalence of lifestyle-related chronic diseases, such as diabetes and COPD, the potential implications for patients with diabetes with overt pulmonary diseases deserve further attention.”

In other respiratory news, acetaminophen use may increase the risk of developing or maintaining asthma, rhinoconjunctivitis, and eczema in adolescents. As Richard Beasley and colleagues reported online in American Journal of Respiratory and Critical Care Medicine, their study of 322,959 13- and 14-year-olds linked recent acetaminophen use with an increased risk of current symptoms of the three conditions.

Finally, vitamin D may be effective in the prevention and treatment of allergy to a common mold that can complicate asthma. Aspergillus fumigatus—one of the most prevalent fungal organisms inhaled—can cause significant allergic symptoms in people with asthma or cystic fibrosis. Vitamin D3 was found to substantially reduce the production of the protein driving the allergic response to A. fumigatus while also increasing production of the proteins that promote allergen tolerance (J Clin Invest. 2010;120:3242-3254).