medwireNews: Researchers have identified modifiable risk factors that if targeted early could help prevent the debilitating consequences of diabetic peripheral neuropathy in young people with type 1 or type 2 diabetes.
“The results of our study suggest that poor glycemic control over time and traditional cardiovascular risk factors are important risk factors associated with [diabetic peripheral neuropathy],” Eva Feldman (University of Michigan, Ann Arbor, USA) and co-authors write in Diabetes Care.
They found that 7% of 1734 adults, younger than 20 years old, with type 1 diabetes and 22% of 258 with type 2 diabetes had diabetic peripheral neuropathy, defined as a Michigan Neuropathy Screening Instrument (MNSI) score above 2.
This more than threefold difference in prevalence, despite both groups having similar glycated hemoglobin levels of around 9% and a comparable duration of diabetes of about 7 years, suggests divergent pathophysiological pathways, say the SEARCH for Diabetes in Youth Study investigators.
“Glycotoxicity and its downstream pathways could be a key player in [type 1 diabetes], while lipotoxicity and insulin resistance could be the major drivers among those with [type 2 diabetes],” they propose.
Risk factors associated with diabetic neuropathy included older age, smoking, cardiovascular risk factors, and longer duration of diabetes, but the researchers point out that poor long-term glycemic control and dyslipidemia emerged as modifiable risk factors common to both groups.
Glycemic control over time, summarized as the area under the curve (AUC) for HbA1c, was worse in patients with than without diabetic neuropathy, and significantly so in patients with type 1 diabetes, at 9.1% versus 8.5%. The difference did not reach statistical significance in patients with type 2 diabetes, possibly because of the relatively small sample size, the researchers suggest.
Logistic regression models showed that long-term glycemic control was significantly associated with diabetic neuropathy in patients with type 1 diabetes after accounting for other risk factors, at an odds ratio of 1.53.
And the team reports a “sharp” twofold increase in the prevalence of diabetic neuropathy between patients with a 5–10-year duration of diabetes compared with more than 10 years, from 5% to 13% in patients with type 1 diabetes and from 19% to 36% in patients with type 2 diabetes.
“Thus, achieving and maintaining good glycemic control (HbA1c ≤7.5%) could go a long way in preventing or delaying the development of [diabetic peripheral neuropathy] and other microvascular complication of diabetes in this young population,” they say.
The AUCs for low-density lipoprotein cholesterol, triglycerides, systolic blood pressure, and diastolic blood pressure were also all significantly higher in patients with type 1 diabetes and diabetic neuropathy compared with those without, while the AUC for high-density lipoprotein (HDL) cholesterol was significantly lower. The same trends were seen in the patients with type 2 diabetes but again the differences did not reach significance.
The association between diabetic neuropathy and lower HDL-cholesterol levels has been previously reported in several landmark trials, note Feldman and team, and they believe it could be “one of the key players in the pathogenesis of [diabetic peripheral neuropathy]” in this cohort.
“Thus, targeting the lower HDL-[cholesterol] levels with interventions such as aerobic exercise, smoking cessation, weight loss, and dietary manipulation, which have been known to increase HDL-[cholesterol] levels by up to 20% and are generally associated with improved glycemic control, could be an additional therapeutic approach beyond optimal glycemic control in this young population,” they conclude.
By Lucy Piper
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