Kimihiko Akimoto

Fasting plasma glucose and HbA1c as risk factors for Type 2 diabetes

Aims   We examined the value of combining fasting plasma glucose (FPG) and glycated haemoglobin (HbA1c) as a predictor of diabetes, using the new American Diabetes Association (ADA) criteria of FPG and lower cut‐off point of HbA1c.

The threshold for definition of impaired fasting glucose in a Japanese population

Aims  We examined whether the cut‐off value of fasting plasma glucose (FPG) for diagnosing impaired fasting glucose (IFG) should be lowered, using data from a large Japanese population.

A two-step screening, measurement of HbA1c in association with FPG, may be useful in predicting diabetes.

Backgrounds We compared the usefulness of fasting plasma glucose (FPG), or hemoglobin A1c (HbA1c), or both in predicting type 2 diabetes. Methods This retrospective cohort study investigated 9,322 Japanese adults (4,786 men and 4,536 women), aged 19–69 yrs, free of diabetes at baseline. Usefulness was assessed by predictive values (PV), sensitivity, specificity, and the area under the receiver operating characteristic curve (AUROC) maximised under the best cut-off point. Results During the average 6 years of follow-up, 221 men (4.6%) and 92 women (2%) developed diabetes. The best cut-off points for FPG (i.e., 5.67 mmol/l for men and 5.5 mmol/l for women) gave excellent AUROC, and the highest positive PV (13% for men and 9% for women) in predicting diabetes. In high risk subjects with FPG 6.1–6.9 mmol/l, 119 men (26.8%) and 39 women (28.3%) developed diabetes. Under the best cut-off points of FPG 6.39 mmol/l and A1c 5.8, AUROC and positive PV for FPG slightly decreased indicating FPG became less useful and were statistically indistinguishable from those for HbA1c in men. In fact, HbA1c was the most useful in women: HbA1c of 6.0% gave the highest positive likelihood ratio of 2.74 and larger AUROC than did FPG. Although AUROC for HbA1c was acceptable and indistinguishable from that for the combined use, HbA1c had higher specificity and positive LR than did the combined use. Conclusions This study demonstrated that FPG was the most useful to predict diabetes in the general population. However, in subjects with FPG 6.1–6.9 mmol/l, FPG became less useful and diagnostic performance of FPG was indistinguishable from that of HbA1c in men whereas HbA1c was the most useful in women. Thus, a two-step screening, measurement of HbA1c in association with FPG, may be useful in predicting diabetes.

Effects of age and sex in the diagnosis of type 2 diabetes using glycated haemoglobin in Japan: the Yuport Medical Checkup Centre study.

Background We examined how the prevalence of individuals diagnosed with diabetes differs by age and sex using the diagnostic criteria of fasting plasma glucose (FPG) and/or glycated haemoglobin (HbA1c) in a large Japanese population. Methods We conducted a cross-sectional study using a dataset of 33,959 people (16,869 men and 17,090 women) without known diabetes who underwent health checkups from 1998 to 2006. We divided the age range of the participants into six groups of similar numbers. We compared the prevalence of diabetes using the criteria of FPG ≥7.0 mmol/l (126 mg/dl), HbA1c ≥48 mmol/mol (6.5%), or both, in men and women in each age group. Results Men had higher prevalence of diabetes than women using the criterion of either FPG or HbA1c (7.5% men vs. 3.4% women, P<0.001), or both (4.3% men vs. 1.8% women, P<0.001). HbA1c increased steadily in women through the six age groups. In the oldest group (≥66 years), the proportion of women among those diagnosed with diabetes was as high as 42.3% (215/508) using the criterion of either FPG or HbA1c, and 41.6% (116/279) using both criteria. Conclusions Using either FPG or HbA1c, the prevalence of people diagnosed with diabetes would almost double compared to using the criterion of both scores, and this would include more elderly women than men. The impact of introducing HbA1c for diabetes diagnosis should be considered in terms of age and sex.

Prevalence and characteristics of non-obese diabetes in Japanese men and women: the Yuport Medical Checkup Center Study.

This study examined the prevalence and characteristics of type 2 diabetes in non‐obese subjects to compare their cardiometabolic markers to those without diabetes.

Impaired fasting glucose as an independent risk factor for hypertension among healthy middle-aged Japanese subjects with optimal blood pressure: the Yuport Medical Checkup Centre retrospective cohort study

BackgroundThis study aimed at investigating whether impaired fasting glucose (IFG) is an independent risk factor for incident hypertension among middle-aged Japanese subjects with optimal blood pressure (OBP).FindingsThis retrospective cohort study was conducted in 2943 non-diabetic and non-hypertensive subjects aged 40–64 years, who participated in a voluntary health check-up program during the baseline (1998–2002) and follow-up periods (2002–2006). A multiple logistic regression model was utilized to calculate the odds ratio (OR) of incident hypertension among men and women with IFG and OBP. OBP was defined as systolic blood pressure (SBP) <120 mmHg and diastolic blood pressure (DBP) <80 mmHg, with no known history of hypertension. In this study, hypertension was defined as SBP ≥140 mmHg and DBP ≥90 mmHg or by a self-reported clinical diagnosis of hypertension. After the mean follow-up period of 5.6 years, the incidence of hypertension in men and women was 5.7% (73/1270) and 3.8% (62/1673), respectively. The age-adjusted ORs for incident hypertension in men and women with IFG were 1.95 (95% CI, 1.21–3.15) and 3.54 (95% CI, 2.00–6.27), respectively. After adjusting for age, systolic blood pressure, body mass index, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and uric acid, the ORs for hypertension were 1.66 (95% CI; 1.02–2.70) for men and 2.62 (95% CI, 1.45–4.73) for women.ConclusionThe study results show that IFG may act as an independent risk factor for developing hypertension in individuals with OBP.

Persistent fasting hyperglycaemia is more predictive of Type 2 diabetes than transient fasting hyperglycaemia

Diabet. Med. 29, e75–e81 (2012)

Do Non-Glycaemic Markers Add Value to Plasma Glucose and Hemoglobin A1c in Predicting Diabetes? Yuport Health Checkup Center Study

Background Many markers have been indicated as predictors of type 2 diabetes. However, the question of whether or not non-glycaemic (blood) biomarkers and non-blood biomarkers have a predictive additive utility when combined with glycaemic (blood) biomarkers is unknown. The study aim is to assess this additive utility in a large Japanese population. Methods We used data from a retrospective cohort study conducted from 1998 to 2002 for the baseline and 2002 to 2006 for follow-up, inclusive of 5,142 men (mean age of 51.9 years) and 4,847 women (54.1 years) at baseline. The cumulative incidence of diabetes [defined either as a fasting plasma glucose (FPG) ≥7.00 mmol/l or as clinically diagnosed diabetes] was measured. In addition to glycaemic biomarkers [FPG and hemoglobin A1c (HbA1c)], we examined the clinical usefulness of adding non-glycaemic biomarkers and non-blood biomarkers, using sensitivity and specificity, and the area under the curve (AUC) of the receiver operating characteristics. Results The AUCs to predict diabetes were 0.874 and 0.924 for FPG, 0.793 and 0.822 for HbA1c, in men and women, respectively. Glycaemic biomarkers were the best and second-best for diabetes prediction among the markers. All non-glycaemic markers (except uric acid in men and creatinine in both sexes) predicted diabetes. Among these biomarkers, the highest AUC in the single-marker analysis was 0.656 for alanine aminotransferase (ALT) in men and 0.740 for body mass index in women. The AUC of the combined markers of FPG and HbA1c was 0.895 in men and 0.938 in women, which were marginally increased to 0.904 and 0.940 when adding ALT, respectively. Conclusions AUC increments were marginal when adding non-glycaemic biomarkers and non-blood biomarkers to the classic model based on FPG and HbA1c. For the prediction of diabetes, FPG and HbA1c are sufficient and the other markers may not be needed in clinical practice.

Prevalence and characteristics of non‐obese diabetes in Japanese men and women: the Yuport Medical Checkup Center Study 日本男性与女性非肥胖者的糖尿病患病率与特征：Yuport医学体检中心研究

This study examined the prevalence and characteristics of type 2 diabetes in non‐obese subjects to compare their cardiometabolic markers to those without diabetes.

Undiagnosed diabetes has poorer profiles for cardiovascular and metabolic markers than known diabetes: The Yuport Medical Checkup Center Study

We compared cardiovascular and metabolic markers between undiagnosed and known diabetes among 3045 subjects who had voluntary health check and no cardiovascular disease. Subjects with undiagnosed diabetes had poorer profiles of these markers than those with known diabetes. Undiagnosed diabetes should be recognized as a condition with these risks.