Metabolic syndrome in normoglycaemic elderly men

Association of fasting glucose and glycated hemoglobin with the long-term risk of incident metabolic syndrome: Korean Genome and Epidemiology Study (KoGES)

AIMS

Previous studies have proposed potential benefit of glycated hemoglobin (HbA1c) supplementary to fasting glucose in detecting metabolic syndrome (MetS). This study was to investigate an association of incident MetS with levels of HbA1c and fasting glucose.

METHODS

In a cohort of Korean Genome and Epidemiology Study, 5515 non-diabetic adults were grouped by the levels of baseline fasting glucose and HbA1c, and followed-up for 10 years. Using multivariate Cox proportional hazards assumption, hazards ratios (HRs) and 95% confidence interval (CI) for incident MetS (adjusted HRs [95% CI]) were calculated according to baseline fasting glucose and HbA1c. In individuals with normal fasting glucose, subgroup analysis was conducted to evaluate an association of HbA1c levels with MetS.

RESULTS

The risk for MetS significantly increased proportionally to fasting glucose ≥ 80 mg/dL and HbA1c ≥ 5.5%, compared with fating glucose < 80 mg/dL and HbA1c < 5.3%, respectively. In subgroups of normal fasting glucose, HbA1c ≥ 5.7% had the increased risk of MetS in fasting glucose < 80 mg/dL (5.7-5.9%: 1.41 [1.07-1.86] and 6.0-6.4%: 2.20 [1.40-2.92]), and HbA1c ≥ 5.5% had the increased risk of MetS in fasting glucose of 80-99 mg/dL (5.5-5.6%: 1.33 [1.08-1.64], 5.7-5.9%: 1.57 (1.27-1.93), and 6.0-6.4%: 2.37 [1.87-3.00]).

CONCLUSIONS

Both elevated fasting glucose and HbA1c were significantly associated with the increased risk of MetS even within normal range. HbA1c is effective in identifying high-risk group for MetS in individuals with normal fasting glucose.

Higher normal range of fasting plasma glucose still has a higher risk for metabolic syndrome: a combined cross-sectional and longitudinal study in elderly

INTRODUCTION

It is well known that higher fasting plasma glucose (FPG) is associated with metabolic syndrome (MetS). This relationship still exists even the FPG is within the normal range. However, most of these studies did not exclude subjects who were on medications which would affect the results of the studies. At the same time, there is no longitudinal study done to validate this correlation, especially in elderly. In this study, the relationships between normal FPG and MetS were evaluated.

METHOD

We randomly selected 57,517 subjects who were ≥ 60-years old from health screening centre. In the first part of study, subjects were enrolled in the cross-sectional study to find out the optimal cut-off value of FPG with higher chances to have MetS. In the second part of current study, subjects with MetS at baseline were excluded from the same study group, and performed a median 5.3-year longitudinal study.

RESULTS

There were 18,287 subjects enrolled in this study. In the first part of study, the cross-sectional study, optimal cut-off values of FPG were determined by the ROC curve and the sensitivity for these cut-off values were 56.6% in men and 60.9% in women, respectively. The result showed that lower FPG is healthier than the higher (log-rank test, p < 0.001). During the follow-up period, 5039 subjects showed hazard ratios of 2.09 for men and 1.884 for women developing future MetS.

CONCLUSION

Our study is the first longitudinal design in elderly and showed that older subjects with higher FPG proved to have higher risk of Mets even the FPG is still within its normal range.