Occupational Hydrocarbon Exposure and Diabetic Nephropathy

Abstract

Exposure to hydrocarbons has been implicated in the pathogenesis of glomerulonephritis but its role in the development of diabetic nephropathy remains unknown. Three groups of patients with Type 1 diabetes of over 10 years duration were studied. Group 1 comprised 45 patients (23 F) with no diabetic nephropathy (urinary albumin excretion (AER) < 30 mg 24 h-1), group 2 comprised 37 patients (17 F) with incipient diabetic nephropathy (AER between 30-300 mg 24 h-1), and group 3 comprised 31 patients (15 F) with overt diabetic nephropathy (AER > 300 mg 24 h-1). The groups were comparable for age, sex, duration of diabetes, recent glycaemic control, social class, and residential area. Patients were assessed blindly by a validated questionnaire and interview for hydrocarbon exposure, consumption of tobacco, analgesic agents, and alcohol. Exposure scores to hydrocarbons derived from the questionnaire were significantly higher in patients with incipient and overt diabetic nephropathy with smoking adjusted odds ratios of 3.6 and 5.2, respectively. The consumption of alcohol, analgesic agents, tobacco, and smoking habits were similar in the three groups. In conclusion, hydrocarbon exposure may be a key environmental factor in the development of diabetic nephropathy in patients with Type 1 diabetes.

Effect of Organic Solvent Exposure on Chronic Kidney Disease Progression

“…The first reported cases were rapidly progressive GN with or without anti-glomerular basement membrane antibodies, a severe but rare type of GN (3). A few cases of membranous nephropathy (MN) (4), IgA nephropathy (IgAN) (5), and FSGS (6) were described later in solvent-exposed workers, but concern definitely rose from a number of case-control studies that included chronic GN as well as other types of chronic kidney disease (CKD) (2,(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21). Although some of these studies were criticized for their methodologic weaknesses with respect to sample size and inaccuracy in case definition or exposure assessment, most of them showed significant associations of solvent exposure with various types of primary or secondary chronic GN (2,7,8,10 -12,14 -19), except for three, which were negative (9,13,21).…”

Absence of Association between Organic Solvent Exposure and Risk of Chronic Renal Failure

“…Our results, however, argue against a promoting effect of any importance, and the etiologic fraction of solvent exposure on CRF, if at all, would be small. Further-more, any major links between solvent exposure and CRF among patients with a clinical diagnosis of either glomerulonephritis or diabetic nephropathy likely would have been detected, considering the strong associations reported in several previous studies (3,9,10,15).…”

“…In the very first investigation published, the exposure scores used were poorly defined (2). The exposure score developed by Ravnskov et al (3) and later used in several studies (6,9,10,15,23,25) represents an improvement, but the assessment scale with exposure intensity factors according to 17 predefined occupational activities was crude and may have led to varying degrees of misclassification.…”

“…Exposure to the solvent subclass oxygenated hydrocarbons was admittedly associated with a fivefold increase in risk, but the CI was wide and no doseresponse relation could be demonstrated. Yaqoob et al (15) showed a significantly greater exposure to organic solvents among patients with insulin-dependent diabetes and diabetic nephropathy as compared with those without diabetic renal disease.…”

“…In one study, solvent exposure was associated with the development of diabetic nephropathy (15), and in two others, solvent exposure was associated with either chronic renal failure (CRF) overall (11) or specific diagnoses suspected to be linked to occupational nephrotoxins (8) albeit without dose-response trends. To evaluate whether organic solvent exposure is a significant factor in the development of CRF overall or in specific subgroups of CRF, we conducted a nationwide population-based case-control study in Sweden of incident CRF, while attempting to avoid the limitations of previous investigations.…”