The retinopathy‐derived HbA1c threshold of 6.5% for type 2 diabetes also captures the risk of diabetic nephropathy in NHANES

Abstract

Aim To determine if an HbA1c diagnostic threshold of less than 6.5% (<48 mmol/mol) could be identified based on a urinary albumin‐creatinine ratio (UACR) of 30 mg/g or higher in subjects not known to have diabetes. Methods A UACR was measured for 20 158 participants in the 2011‐2018 nationally representative cross‐sectional National Health and Nutrition Examination Surveys (NHANES; cycles 7‐10 inclusive). Results There was a significant trend for an increasing risk with a UACR of 30 mg/g or higher across increasing HbA1c categories (P < .0001). This trend was mainly attributable to the high prevalence of raised UACR in the 7.0% or higher HbA1c subgroup of subjects not previously diagnosed with diabetes. None of the odds ratios in the lower HbA1c subgroups versus the HbA1c subgroup of less than 5.0% reached significance. There were racial/ethnic differences in UACR risk (P < .0001), with White and Black subjects exhibiting little increased risk (vs. HbA1c <5.0%) until they reached an HbA1c of 7.0%, while Asian and Hispanic subjects showed some increased, but non‐significant, risks at lower HbA1c levels. Maximizing the area under receiver operating characteristic curves from logistic regressions predicted an ideal HbA1c threshold of 5.8%, but there was little variation in area from 5.5% to 7.0%. Conclusion A clinically useful diagnostic threshold below 6.5% for HbA1c for elevated UACR risk was not identified, with an increased risk only obvious at an HbA1c of 7.0% or higher. Thus, the retinopathy‐derived HbA1c threshold of 6.5% also captures the risk of diabetic nephropathy in NHANES.

Increased Glycemic Variability Evaluated by Continuous Glucose Monitoring is Associated with Osteoporosis in Type 2 Diabetic Patients

“…Results from Atkin et al. study showed that the HbA1c threshold of 6.5% for DR also elevated the risk of diabetic nephropathy (DN) ( 9 ). The INTERPRET-DD study involved in 2,733 subjects with T2DM from 14 countries revealed that each 1% increase in HbA1c level generates an 11 % increased risk of diabetic peripheral neuropathy (DPN) ( 10 ).…”

Identifying Distinct Risk Thresholds of Glycated Hemoglobin and Systolic Blood Pressure for Rapid Albuminuria Progression in Type 2 Diabetes From NHANES (1999–2018)

“…Another study found a significantly increased risk of albuminuria in participants with HbA1c ≥ 7% compared with the normal urinary protein population. The above results remained stable in diabetic and non-diabetic populations ( 15 ). This might suggest a threshold effect between HbA1c and ACR levels, but a lack of large-scale population studies targeting patients with T2DM.…”

Development and Validation of a Model That Predicts the Risk of Diabetic Nephropathy in Type 2 Diabetes Mellitus Patients: A Cross-Sectional Study

“… 45 Atkin et al showed that the proportion of subjects with elevated urinary albumin creatinine ratios was significantly higher in subjects with HbA1c levels greater than or equal to 7.0% compared to those with HbA1c levels below 5.0%. 46 This further reflects that high HbA1c increases the risk of DN.…”