Glycated haemoglobin and cardiovascular risk factors in Chinese subjects with normal glucose tolerance

Abstract

Increased plasma glucose concentration is a predictive factor for mortality in both diabetic and non-diabetic subjects. Although glycated haemoglobin (HbA1c) is a useful index of mean blood glucose concentrations over the preceding 1 to 3 months, there are few data regarding its relationship to cardiovascular risk. We have examined the relationship between HbA1c and cardiovascular risk factors in 1280 subjects with normal glucose tolerance. Based on HbA1c tertiles (tertile 1: n = 427, 262 men and 165 women, HbA1c level: 2.9-4.7% in men and 3.2-4.2% in women; tertile 2: n = 426, 261 men and 165 women, HbA1c level: 4.7-5.1% in men and 4.2-4.6% in women; tertile 3: n = 427, 262 men and 165 women, HbA1c level: 5.1-6.7% in men and 4.6-6.9% in women), increasing HbA1c was associated with increasing age, blood pressure, waist-hip ratio, fasting and 2-h plasma glucose, 2-h insulin, cholesterol, low-density lipoprotein cholesterol, apolipoprotein B and urate concentrations. When age and sex were included as covariates, increasing HbA1c remained associated with increasing fasting and 2-h plasma glucose, 2-h insulin, total cholesterol, and low-density lipoprotein cholesterol concentrations. These findings emphasize the importance of hyperglycaemia, as reflected by HbA1c, as a continuum in the evaluation of cardiovascular risk. Furthermore, these findings support the hypothesis that cardiovascular disease risk commences with rising glucose concentrations before 'conventionally-defined' glucose intolerance occurs.

Effect of Aging on A1C Levels in Individuals Without Diabetes

“…Even though the association of A1C with complications is well established in individuals with diabetes (31) and in nondiabetic subjects (32,33), the clinical significance of increased A1C in the subset of older individuals who have no evidence of glucose intolerance is unknown. Current treatment targets for patients with diabetes are similar regardless of age.…”

Haemoglobin A1c levels and subsequent cardiovascular disease in persons without diabetes: a meta-analysis of prospective cohorts

“…After reading the full text, there were 26 potentially acceptable studies that were rejected at the final stage: 14 did not have appropriate data [1,[13][14][15][16][17][18][19][20][21][22][23][24][25]; four did not involve outcomes of interest [26][27][28][29]; three studied non-relevant populations [30][31][32]; three were duplicates [33][34][35]; and two were editorials/review papers [36,37]. That left seven papers for analysis [38][39][40][41][42][43][44].…”

Association of A1C With Cardiovascular Disease and Metabolic Syndrome in Asian Indians With Normal Glucose Tolerance

“…Similar findings were reported in African Americans (33). However, unlike the Chinese study in which age and sex altered some of these associations (31), in the present analysis adjustments for age and sex did not alter the association of A1C with CVD risk factors.…”