Chikako Ito

Correlation among fasting plasma glucose, two-hour plasma glucose levels in OGTT and HbA1c

A study was made on the association among 2-h plasma glucose (PG) in oral glucose tolerance test (OGTT), fasting plasma glucose (FPG) using correlation and regression equation. Subjects were 13174 OGTT examinees tested between 1980 and 1998. Blood glucose was determined by the glucose oxidase method and glycated hemoglobin (HbA1c) by the HPLC method. As for correlation between 2-h PG and FPG, regression equation of the <60 year group was y=57.1+0.336x (r=0.866, P<0.0001) and that of the >==60 year group was y=61.5+0.286x (r=0.814, P<0. 0001). FPG was calculated at 124.3 in the <60 year group and 118.7 mg/dl in the >==60 year group for 2-h PG of 200 mg/dl, 2-h PG were calculated at 199.5 and 210.7 mg/dl for FPG of 126 mg/dl, respectively. In the <60 year group, FPG were calculated at 121.7 and 124.4 mg/dl and 2-h PG at 193.2 and 199.3 mg/dl for HbA1c of 6.0 and 6.1%, respectively. As for associations between HbA1c and FPG or 2-h PG being high correlation, it is possible to estimate a prevalence of DM in a group using HbA1c>==6.1%. High correlations were demonstrated among all the three measures; FPG, 2-h PG, HbA1c. If 2-h PG is used in diagnosing diabetes mellitus, an FPG of 126 mg/dl proposed by ADA and World Health Organization (WHO) as a diagnostic level of FPG is an acceptable value for the Japanese.

Importance of OGTT for diagnosing diabetes mellitus based on prevalence and incidence of retinopathy

Study was made on the necessity and importance of the oral glucose tolerance test (OGTT) for diagnosing diabetes mellitus based on prevalence and incidence of diabetic retinopathy. Subjects were 12208 persons undergoing OGTT between 1965 and 1997. The prevalence of retinopathy was significantly elevated with FPG>/=126 and 2-h PG>/=198 mg/dl. The incidence of retinopathy was 15-30/10000 person-years (PY) with FPG<125, but with FPG of 126-139 it was significantly higher (69/10000 PY) and at 140-199 mg/dl it was elevated to 139/10000 PY. Subjects were classified at initial test into FPG<110, 110-125, 126-139, and >/=140 and further into 2-h PG<200 and >/=200 mg/dl for comparison with the incidence of retinopathy. Even with the same FPG, the incidence was two- to threefold higher with 2-h PG>/=200 mg/dl, indicating that 2-h PG was highly associated with the incidence of retinopathy. As for IFG, the prevalence of diabetes as defined by 2-h PG>/=200 in the OGTT increased with elevated FPG, and 33.7% of IFG cases showed 2-h PG>/=200 mg/dl. Based on the prevalence and incidence of retinopathy, we conclude that 126 mg/dl FPG is an appropriate cut-off level, and the OGTT is important for diagnosing mild diabetes mellitus.

The impact of visceral adipose tissue and high-molecular weight adiponectin on cardio-ankle vascular index in asymptomatic Japanese subjects.

Few studies addressed the relation of visceral adiposity and high-molecular weight (HMW) adiponectin to arterial stiffness. We investigated the impact of visceral adipose tissue (VAT) and HMW adiponectin on cardio-ankle vascular index (CAVI) in asymptomatic Japanese subjects. We studied 487 consecutive subjects (271 men and 216 women) who underwent general health examination between October 2005 and May 2008. The abdominal, visceral, and subcutaneous adipose tissue areas were determined by low-dose x-ray computed tomography. Serum levels of total and HMW adiponectin were measured using the enzyme-linked immunosorbent assay system based on a monoclonal antibody to humans. Cardio-ankle vascular index was positively correlated with VAT area and negatively correlated with HMW adiponectin levels. We also found the positive association of the number of metabolic syndrome components with CAVI in both sexes. A stepwise multiple regression analysis revealed that age, VAT area, serum HMW adiponectin levels, and homeostasis model assessment of insulin resistance were independent determinants of CAVI. Receiver operating characteristic analyses demonstrated that the predictive value of the VAT area for the extent of CAVI (mild: <25th percentile vs severe: >75th percentile) exceeded that of total or HMW adiponectin levels in both sexes. In conclusion, increased CAVI is associated with both amounts of VAT measured by computed tomography and serum HMW adiponectin levels in asymptomatic Japanese subjects. Receiver operating characteristic analysis indicates that the VAT area is a lot better predictor of arterial stiffness than adiponectin levels.

Is there any association between subcutaneous adipose tissue area and plasma total and high molecular weight adiponectin levels

This study was conducted for the purpose of clarifying the correlations between the subcutaneous adipose tissue area and plasma total and high-molecular weight (HMW) adiponectin levels. The subjects of this study comprised 359 men and 142 women who underwent general health examinations from October 2005 to December 2006. The abdominal subcutaneous and visceral adipose tissue areas were measured using low-dose x-ray computed tomography. Total and HMW adiponectin levels were measured using the enzyme-linked immunosorbent assay system based on a monoclonal antibody to humans. There were negative correlations between the plasma total and HMW adiponectin levels and visceral and subcutaneous adipose tissue areas using simple correlation analysis. Multiple linear regression analysis clearly indicated that the subcutaneous adipose tissue area was independently correlated with the HMW adiponectin levels in men and closely related in women. Many studies reported that only the visceral adipose tissue area showed a significant correlation with metabolic syndrome. However, these results clearly indicate that it is also important to consider the subcutaneous adipose tissue area in metabolic syndrome.

Prediction of diabetes mellitus (NIDDM)

This study was made to analyze predictive NIDDM markers using a long-term GTT follow-up observation period of 1-30 years. Subjects of this study were 5446 cases (3994 males, 1452 females). Results are as follows: (1) NIDDM development rate increased gradually with increasing 2 h-PG levels at GTT, but for groups with 2 h-PG > or = 170 mg/dl, the rate rose rapidly. (2) PG at GTT was higher in the NIDDM development group than in the control group. Mean 1 h-PG reached > or = 200 mg/dl for 4 years before onset in the NIDDM group. Frequency of 1 h-PG > or = 200 mg/dl was 54% 4 years before and 67% 1 year before onset. (3) The highest NIDDM prediction accuracy was in 1 h-PG levels of 200 mg/dl or more and/or 2 h-PG levels of 170 mg/dl or more. Sensitivity was 75.2%, and specificity, 63.4% within 3 years before onset. (4) With addition of delta IRI/delta PG, sensitivity increased, but specificity decreased. (5) The highest relationship with NIDDM development was for high PG levels (1 h-PG > or = 200 mg/dl and/or 2 h-PG > or = 170 mg/dl), the odds ratio being 5.65. The odds ratio of delta IRI/delta PG was lower than ratio of high PG levels. (6) NIDDM development rate increased about 50% in the under-60-years age group and in the group of BMI > or = 25.

Association between the postprandial glucose Levels and arterial stiffness measured according to the cardio-ankle vascular index in non-diabetic subjects.

OBJECTIVEnAlthough a relationship between post-challenge hyperglycemia and arterial stiffness has been reported, the relationship between the postprandial glucose levels and cardio-ankle vascular index (CAVI) in non-diabetic subjects is not clear. This study thus evaluated the association between the postprandial glucose levels after a composite meal and the degree of arterial stiffness measured according to CAVI in non-diabetic subjects.nnnMETHODSnThe subjects included 1,291 individuals (655 men and 636 women; mean age, 48.6 years; range, 23-85 years) who underwent medical examinations, including blood tests and CAVI assessments, between October 2005 and April 2012. The 1-hour postprandial glucose levels were determined after a 600-kcal traditional Japanese meal.nnnRESULTSnThe CAVI values were significantly higher in the subjects with higher 1-hour postprandial glucose levels (≥140 mg/dL in men; ≥158 mg/dL in women). A simple regression analysis indicated that the CAVI values were significantly correlated with the 1-hour postprandial glucose levels in men (r=0.286, p<0.0001) and women (r=0.228, p<0.0001). After adjusting for age, BMI, systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, 1-hour postprandial glucose, homeostatis model assessment of insulin resistance, estimated glemerular filtration rate, and high sensitive C-reactive protein, stepwise multiple regression analysis demonstrated that the 1-hour postprandial glucose level was an independent predictor associated with the CAVI in men (p=0.003) and older women 50 years of age or older (p=0.003).nnnCONCLUSIONnThis study demonstrated that the 1-hour postprandial glucose levels are associated with increased CAVI values in non-diabetic men and older women 50 years of age or older.

Second derivative of the finger photoplethysmogram and cardiovascular mortality in middle-aged and elderly Japanese women.

The second derivative of the digital photoplethysmogram (SDPTG) is an indicator of arterial stiffness. The ratio of the height of the d wave to the a wave of the SDPTG (d/a) is associated with functional peripheral vascular tension and represents aortic-blood pressure (BP) augmented by reflection waves from the periphery. This longitudinal study aimed to investigate the relationship between SDPTG and cardiovascular mortality in middle-aged and elderly Japanese women. From 1998 to 2008, we recruited 4373 women (50–79 years old at baseline) who underwent medical check-ups and SDPTG measurement. The SDPTG index (d/a) was calculated from the wave component height, and was divided into quartiles (Q) according to the d/a value. The median follow-up period was 9.0 years. The d/a value was negatively associated with age and BP, and positively associated with heart rate and body height. Using the Cox proportional hazards model, the hazard ratios for cardiovascular mortality for Q2, Q3 and Q4 were significantly higher than that of Q1. In multivariate analysis, the hazard ratio was 2.30 for Q3 (95% confidence interval (CI): 1.06–4.99, P<0.05) and 2.60 for Q4 (95% CI: 1.21–5.60, P<0.05), after adjustment for age, height, body mass index, BP levels, heart rate and other atherosclerosis-related factors. The hazard ratios of cardiovascular mortality for Q3 and Q4 were significantly higher compared with the reference (Q1). Thus, the SDPTG d/a is an independent predictor of cardiovascular mortality in middle-aged and elderly Japanese women.