Association of Long-Term Air Pollution with Prevalence and Incidence of Distal Sensorimotor Polyneuropathy: KORA F4/FF4 Study

Abstract

Background: Air pollution contributes to type 2 diabetes and cardiovascular diseases, but its relevance for other complications of diabetes, in particular distal sensorimotor polyneuropathy (DSPN), is unclear. Recent studies have indicated that DSPN is also increasingly prevalent in obesity. Objectives: We aimed to assess associations of air pollutants with prevalent and incident DSPN in a population-based study of older individuals with high rates of type 2 diabetes and obesity. Methods: Cross-sectional analyses on prevalent DSPN were based on 1,075 individuals 62–81 years of age from the German Cooperative Health Research in the Region of Augsburg (KORA) F4 survey (2006–2008). Analyses on incident DSPN included 424 individuals without DSPN at baseline (KORA F4), of whom 188 had developed DSPN by the KORA FF4 survey (2013–2014). Associations of annual average air pollutant concentrations at participants’ residences with prevalent and incident DSPN were estimated using Poisson regression models with a robust error variance adjusting for multiple confounders. Results: Higher particle number concentrations (PNCs) were associated with higher prevalence [risk ratio (RR) per interquartile range (IQR) (95% CI: 1.01, 1.20)] and incidence [1.11 (95% CI: 0.99, 1.24)] of DSPN. In subgroup analyses, particulate (PNC, , , , and ) and gaseous ( , ) pollutants were positively associated with prevalent DSPN in obese participants, whereas corresponding estimates for nonobese participants were close to the null [e.g., for an IQR increase in PNC, (95% CI: 1.05, 1.31) vs. 1.06 (95% CI: 0.95, 1.19); ]. With the exception of , corresponding associations with incident DSPN were positive in obese participants but null or inverse for nonobese participants, with [e.g., for PNC, (95% CI: 1.08, 1.51) vs. 1.03 (95% CI: 0.90, 1.18); ]. Discussion: Both particulate and gaseous air pollutants were positively associated with prevalent and incident DSPN in obese individuals. Obesity and air pollution may have synergistic effects on the development of DSPN. https://doi.org/10.1289/EHP7311

Ambient Air Pollutants and Incident Microvascular Disease: A Cohort Study

“…However, the significant results were seen among obese individuals only, which may result from a chance finding as the study sample size was very limited (n = 424). 10 Pope et al examined the association between 30-year averaged exposure to ambient hydrogen sulfide (H 2 S) and the risk of peripheral neuropathy in a sample of 1637 participants in New Zealand, but they found no evidence of adverse effects. 37 Of note, although the results of the current study cannot be directly compared with others due to the lack of data, exposure to air pollution has been associated with several neurological disorders.…”

“…7 Despite this, epidemiological studies investigating the association between air pollutants and risk of microvascular disease are limited. Existing evidence, however, has been mainly focused on specific microvascular disease such as retinopathy, 8,9 peripheral neuropathy, 10 or chronic kidney disease, 11−13 or is restricted to a particularly high-risk population (e.g., patients with diabetes). 8,9 Thus, the associations of various air pollutants with risk of overall microvascular disease among the general population are far from being fully elucidated.…”

Effect of obesity on the associations of 25-hydroxyvitamin D with prevalent and incident distal sensorimotor polyneuropathy: population-based KORA F4/FF4 study

“…This study was based on data from the Cooperative Health Research in the Region of Augsburg (KORA) F4 study (2006–2008) and KORA FF4 study (2013–2014), both follow-up examinations of the population-based KORA S4 study (1999–2001) conducted in Augsburg and two adjacent counties in Southern Germany. The design of the KORA study has been described elsewhere [ 32 ]. The study was carried out in accordance with the Declaration of Helsinki, including obtaining written informed consent from all participants and approved by the ethics board of the Bavarian Chamber of Physicians (Munich, Germany).…”

“…MNSI was extended by bilateral examination of sensory perception using a 10-g monofilament (Neuropen) (0 = normal, 1 = abnormal), resulting in a total MNSI score ranging from 0 (all aspects are normal) to a maximum of 10 points. An MNSI score >2 points was used to define prevalent and incident DSPN as previously suggested [ 32 , 35 ]. This definition satisfies the diagnostic criteria for “possible DSPN” according to the Toronto Diabetic Neuropathy Expert Group [ 36 ].…”

“…Information on the regular use of lipid-lowering drugs and non-steroidal anti-inflammatory drugs (NSAIDs) during the last 7 days was collected through a database-supported computer software as described in detail elsewhere [ 32 ]. Briefly, participants were asked to bring all medications to the study center for verification of use.…”