The period effect in the prevalence of proliferative diabetic retinopathy, gross proteinuria, and peripheral neuropathy in type 1 diabetes: A longitudinal cohort study

Abstract

AimsTo investigate whether, for a specific duration of type 1 diabetes, there is a significant change in the prevalence of proliferative diabetic retinopathy, gross proteinuria and peripheral neuropathy in those more recently diagnosed with diabetes (a period effect), in the Wisconsin Epidemiologic Study of Diabetic Retinopathy. Where present, to determine how common risk factors for diabetic complications might be associated with it, and what might be driving it.Materials and methodsLongitudinal cohort study with seven examination phases between 1980 and 2014. Multivariate logistic regression models and ordinal parameterization were used to test for and evaluate any period effect.ResultsThere is a period effect in the prevalence of gross proteinuria and peripheral neuropathy (decreasing), as seen with proliferative diabetic retinopathy (p < 0.001). Adjusting for changing levels of common risk factors attenuates the period effect, particularly for proliferative diabetic retinopathy. For gross proteinuria and peripheral neuropathy, however there is a persistent period effect in spite of adjusting for the major risk factors.ConclusionsThere are period effects in the prevalence of proliferative diabetic retinopathy, gross proteinuria and peripheral neuropathy that cannot be fully explained by changes in common risk factors for complications of type 1 diabetes in this cohort. The role of other potential confounders warrants further exploration.

Clinical Characteristics and Degree of Glycemic and Cardiovascular Risk Factor Control in Patients with Type 1 Diabetes in Catalonia (Spain)

“…Interestingly, the prevalence of retinopathy was lower than in a similarly designed study from the UK [ 26 ]. Similarly, the prevalence of other microvascular complications was lower than previously published results [ 27 ]. Macrovascular complications showed a similar pattern that of microvascular complications but with much lower prevalence.…”

Decreasing prevalence of retinopathy in childhood‐onset type 1 diabetes over the last decade: A comparison of two cohorts diagnosed 10 years apart

“…Advances in glucose‐lowering treatment may have led to improved glycaemic control over the years and, consequently, decreased prevalence of DR. Indeed, downward trends were reported by many authors, 6‐9 and were apparently more pronounced from the early 1990s onward 10 . However, it is difficult to compare the magnitude of such reductions, as duration of disease, age and calendar year at diagnosis differ among study populations.…”

“…Indeed, downward trends were reported by many authors, [6][7][8][9] and were apparently more pronounced from the early 1990s onward. 10 However, it is difficult to compare the magnitude of such reductions, as duration of disease, age and calendar year at diagnosis differ among study populations. In addition, the effect of diabetes duration may be modified by age at onset [11][12][13] and year of diagnosis.…”

“…In addition, the effect of diabetes duration may be modified by age at onset [11][12][13] and year of diagnosis. 10 Finally, studies that considered longer durations of disease, of about 20 years, refer to diagnoses made long ago, in 1965-1990, 6,14,15 while those that considered more recent years of onset and modern glucose-lowering approaches had shorter durations, of around 7-12 years. [16][17][18] In this study, for the prevalence of DR, we compared two cohorts of patients who had been diagnosed with T1D in their childhood 10 years apart, one in the early 2000s and the other in the early 1990s.…”

“…However, it is difficult to compare the magnitude of such reductions, as duration of disease, age and calendar year at diagnosis differ among study populations. In addition, the effect of diabetes duration may be modified by age at onset 11‐13 and year of diagnosis 10 . Finally, studies that considered longer durations of disease, of about 20 years, refer to diagnoses made long ago, in 1965‐1990, 6,14,15 while those that considered more recent years of onset and modern glucose‐lowering approaches had shorter durations, of around 7‐12 years 16‐18 …”