Estimating the attributable risk of vascular disorders in different ranges of fasting plasma glucose and assessing the effectiveness of anti-diabetes agents on risk reduction; questioning the current diagnostic criteria.

Abstract

Attributable risk of cardiovascular disorders (CVDs) and chronic kidney disease (CKD) in association with diabetes and pre-diabetes is under debate. Moreover, the role of anti-diabetes agents in risk reduction of such conditions is obscure. The purpose of this work is to define the population attributable fraction (PAF) of CVDs and CKD in different rages of plasma glucose. Iranian stepwise approach for surveillance of non-communicable disease risk factors (STEPs) was used to calculate PAF in four subsequent phases. Phase 0: whole population regardless of diagnosis; Phase I: in three CVD risk groups: minimal risk (FPG < 100mg/dL), low risk (FPG 100-126mg/dL), and high risk (FPG ≥ 126mg/dL) groups; Phase II: three diagnostic groups: normal, pre-diabetes, and diabetes; Phase III: diabetes patients either receiving or not receiving anti-diabetes agents. A total of 19,503 participants [female-to-male ratio 1.17:1] had at least one FPG measurement and were enrolled. Phase 0: PAF of young adults was lower in the general population (PAF range for CVDs 0.05 ─ 0.27 [95% CI 0.00 ─ 0.32]; CKD 0.03 ─ 0.41 [0.00 ─ 0.62]). Phase I: High-risk group comprised the largest attributable risks (0.46 ─ 0.97 [0.32 ─ 1]; 0.74 ─ 0.95 [0.58 ─ 1]) compared to low-risk (0.16 ─ 0.41 [0.04 ─ 0.66]; 0.29 ─ 0.35 [0.07 ─ 0.5]) and minimal risk groups (negligible estimates) with higher values in young adults. Phase II: higher values were detected in younger ages for diabetes (0.38 ─ 0.95 [0.29 ─ 1]; 0.65 ─ 0.94 [0.59 ─ 1] and pre-diabetes patients (0.15 ─ 0.4 [0.13 ─ 0.45]; 0.26 ─ 0.35 [0.22 ─ 0.4]) but not normal counterparts (negligible estimates). Phase III: Similar estimates were found in both treatment (0.31 ─ 0.98 [0.17 ─ 1]; 0.21 ─ 0.93 [0.12 ─ 1]) and drug-naïve (0.39 ─ 0.9 [0.27 ─ 1]; 0.63 ─ 0.97 [0.59 ─ 1]) groups with larger values for younger ages. Globalized preventions have not effectively controlled the burden of vascular events in Iran. CVDs and CKD PAFs estimated for pre-diabetes were not remarkably different from normal and diabetes counterparts, arguing current diagnostic criteria. Treatment strategies in high-risk groups are believed to be more beneficial. However, the effectiveness of medical interventions for diabetes in controlling CVDs and CKD burden in Iran is questionable.