Study Highlights Risk Factors for Renal Disease in Patients With T1D

Blood pressure, cholesterol, and body mass index (BMI)—in addition to glycated hemoglobin (A1C)—all appear to be risk factors for renal complications in children and young adults with T1D, according to a new analysis.

Diabetic nephropathy is a major problem for patients with T1D, with some studies suggesting as many as 4 in 10 patients with T1D will develop renal complications. Yet, corresponding author Shilan Seyed Ahmadi, PhD, of Sweden’s University of Gothenburg, and colleagues noted that aside from lowering A1C, the guidelines for monitoring and preventing kidney disease are inconsistent and sometimes lacking in evidence.

In a new report in Acta Diabetologica, Ahmadi and colleagues discussed their analysis of patient characteristics from the Swedish National Diabetes Registry and a similar national pediatric database. The authors found 9347 children and young adults who were registered in the database between 1998 and 2017. Patients were followed from registration through the end of 2017. The cohort had a mean age of 15.3 years and an average diabetes duration of 1.4 years at the start of follow-up. The median follow-up period was 12 years.

“In this population-based cohort study using pediatric and adult registries in Sweden, we aimed to evaluate what levels of blood lipids, blood pressure and BMI in persons with T1D are related to risk of nephropathy,” the authors explained, adding that they also sought to rank those factors, along with A1C and smoking, in terms of their risk contribution to diabetic neuropathy.

Most of the patients in the study—92.1%—remained within normal albuminuric parameters throughout the follow-up period, but 737 people developed abnormal levels, including 132 who developed macroalbuminuria.

Blood pressure at or above 140/80 mmHg, triglycerides at or above 1.0 mmol/L, total cholesterol equal to or above 5.0 mmol/L, high-density lipoprotein (HDL) cholesterol below 1.0 mmol/L, low-density lipoprotein (LDL) 3.5- under 4.0 mmol/L, and BMI at or above 30 were all associated with an increased risk of albuminuria, the analysis showed.

The importance of each risk factor varied depending on the specific category. A1C was the strongest risk factor for any albuminuria and for macroalbuminuria specifically. After A1C, the highest risk factors for any albuminuria were (in order) diastolic blood pressure, triglycerides, systolic blood pressure, total cholesterol, and LDL. HDL blood pressure, BMI, and smoking did not appear to have an impact on the risk of any albuminuria.

For macroalbuminuria specifically, after A1C, the risk factors were total cholesterol, systolic blood pressure, diastolic blood pressure, and triglycerides. The other factors, including smoking, did not appear to impact risk levels.

Ahmadi and colleagues noted that the study could have implications for clinical practice. For instance, caregivers are often cautious about giving blood pressure and cholesterol medications to children due to the risk of side effects, the authors noted. For physicians, it can be difficult to know when to prescribe such medications, since experts have debated whether interventions should be started at a systolic blood pressure of 130 mmHg or 140 mmHg.

“This study supports the higher blood pressure level, but at repeated determinations above these values, younger individuals should also get antihypertensive drugs,” the authors said. They added that stricter blood pressure control is likely particularly important in patients with poor glycemic control.

In terms of prescribing statins to patients with increased LDL and cholesterol levels, “one should first exclude familial hypercholesterolemia and then consider medication if dietary advice is not enough,” the investigators said.

The BMI findings of the study also support the idea that obesity avoidance should be a key goal of patient care, they said.

“The current findings are essential for patients and care-givers where treatment for blood pressure, lipids and obesity have potential adverse effects and require major health care resources,” Ahmadi and colleagues concluded. “Somewhat more tight blood pressure control is indicated in patients with poor glycemic control being at high risk of nephropathy.”

Reference:

Seyed Ahmadi S, Pivodic A, Svensson A, et al. Risk factors for nephropathy in persons with type 1 diabetes: a population-based study. Acta Diabetol. Published online February 24, 2022. doi:10.1007/s00592-022-01863-6