Risk of proteinuria among individuals with persistent borderline diabetes: the Saku study

Risk of developing type 2 diabetes according to blood pressure levels and presence or absence of hypertensive treatment: the Saku study

The aim was to investigate the risk of developing type 2 diabetes according to blood pressure (BP) levels and presence or absence of hypertensive treatment. This 5-year cohort study comprised 3508 Japanese adults aged 30-74 years without diabetes who had undergone a medical checkup including a 75-g oral glucose tolerance test (OGTT) between April 2008 and March 2009 at Saku Central Hospital. Participants receiving antihypertensive treatment were categorized into controlled hypertension ( < 140/90 mmHg) or uncontrolled hypertension ( ≥ 140/90 mmHg) groups. Participants not receiving antihypertensive treatment were categorized: optimal BP ( < 120/80 mmHg), normal BP (120-129/80-84 mmHg), high-normal BP (130-139/85-89 mmHg), grade I hypertension (140-159/90-99 mmHg), and grade II/III hypertension ( ≥ 160/100 mmHg). Hazard ratios and 95% confidence intervals for the incidence of type 2 diabetes as defined by the 75-g OGTT were estimated using multivariable-adjusted Cox proportional hazard models in reference to optimal BP. During an average of 4.4 years of follow-up, 295 participants developed type 2 diabetes. Those with high-normal BP, grade I hypertension, grade II/III hypertension, and uncontrolled hypertension were at significantly higher risk for developing type 2 diabetes, with hazard ratios (95% confidence intervals) of 1.53 (1.03-2.29), 1.53 (1.02-2.32), 2.19 (1.01-4.77), and 1.81 (1.10-2.99), respectively. In conclusion, compared with those with optimal BP, individuals with BP ≥ 130/85 mmHg not receiving antihypertensive treatment and uncontrolled hypertensives with BP ≥ 140/90 mmHg receiving antihypertensive treatment were at a significantly higher risk for developing type 2 diabetes.

Association between alcohol consumption and incidence of impaired insulin secretion and insulin resistance in Japanese: The Saku study

AIMS

To investigate the effect of alcohol consumption on impaired insulin secretion and insulin resistance in Japanese.

METHODS

The participants in this 5-year cohort study were 2100 Japanese aged 30-74 years without type 2 diabetes mellitus, impaired insulin secretion, or insulin resistance who underwent a medical checkup including 75-g OGTT between April 2008 and March 2009 at Saku Central Hospital. Alcohol consumption was categorized as follows: non-drinker (0 g/week), light drinker (1-139 g/week in men and 1-69 g/week in women), moderate drinker (140-274 g/week in men and 70-139 g/week in women) and heavy drinker (≥275 g/week in men and ≥140 g/week in women). The hazard ratios (HRs) and 95% CIs among light to heavy drinkers for incidence of impaired insulin secretion (insulinogenic index ≤51.7) and insulin resistance (HOMA-IR ≥ 2.5), detected by an OGTT at the time of a follow-up medical checkup before the end of March 2014, were estimated by multivariable adjusted Cox proportional hazard models as reference values for non-drinkers.

RESULTS

There were 708 cases of impaired insulin secretion and 191 cases of insulin resistance. The HRs (95% CIs) for impaired insulin secretion in light, moderate and heavy drinkers were 1.16 (0.96-1.40), 1.35 (1.07-1.70) and 1.64 (1.24-2.16), respectively (P for trend <0.001). For insulin resistance, the HRs were 1.22 (0.84-1.76), 1.42 (0.91-2.22) and 1.59 (0.96-2.65), respectively (P for trend = 0.044).

CONCLUSION

Alcohol consumption was positively associated with the incidence of both impaired insulin secretion and insulin resistance.

Impact of metabolic syndrome on the incidence of type 2 diabetes in middle-aged Japanese individuals with impaired insulin secretion: the Saku study

AIMS

To assess the impact of metabolic syndrome (MetS) on the incidence of type 2 diabetes in middle-aged Japanese individuals with impaired insulin secretion (IIS).

METHODS

This cohort study included 1,702 individuals aged 40-59 without diabetes at baseline who underwent a comprehensive medical check-up between April 2008 and March 2009 at Saku Central Hospital. Participants were classified according to their IIS and insulin resistance (IR) status [normal, isolated IR (i-IR), or isolated IIS (i-IIS)] and MetS (presence or absence). They were followed up until March 2014. Type 2 diabetes was defined based on fasting and 2-h post-load plasma glucose concentrations and by the receipt of medical treatment for diabetes.

RESULTS

During 7,572 person-years of follow-up, 92 individuals developed type 2 diabetes. The incidence rates (/1,000 person-years) for type 2 diabetes in the normal without MetS, normal with MetS, i-IR without MetS, i-IR with MetS, i-IIS without MetS, and i-IIS with MetS groups were 5.3, 3.7, 11.3, 24.7, 16.7, and 59.5, respectively. The multivariable-adjusted hazard ratios (HRs) and 95 % confidence intervals (CIs) for type 2 diabetes in the normal with MetS, i-IR with MetS, and i-IIS with MetS groups, relative to the normal without MetS group, were 0.52 (0.12-2.25), 3.78 (1.93-7.42), and 7.94 (3.96-15.91), respectively. Additionally, a positive association of MetS with type 2 diabetes was observed in the i-IIS group [HR (95 % CI) 3.56 (1.88-6.73)] but not in the normal and i-IR groups.

CONCLUSIONS

The prevention of MetS is important, particularly in individuals with low insulin secretion.