Thresholds of risk factors for ischemic stroke in type 2 diabetic patients with and without albuminuria: a non-linear approach

Cardiovascular risk profiles in Type 2 diabetes and the impact of geographical setting

Cardiovascular (CV) disease is a leading morbidity and mortality in Type 2 diabetes (T2DM). Previous studies have shown geographic differences in the prevalence of CV and renal diseases. A literature review of longitudinal (≥5 years) studies including ≥1000 T2DM patients and reporting CV endpoints was performed to compare risk profiles. Key differences between geographies included a relatively higher prevalence of microalbuminuria in East Asian relative to North American and European patients, which in turn is an important CV risk factor. Patients from East Asia also have a relatively higher incidence of stroke and lower incidence of coronary heart disease. Overall, there are differences in CV risk in T2DM patients between different regions and that long-term studies from Africa, the Middle East and Latin America are lacking.

Additive effect of aldose reductase Z-4 microsatellite polymorphism and glycaemic control on cataract development in type 2 diabetes

AIMS

To examine the additive effect of the z-4 microsatellite polymorphism of aldose reductase gene (ALR2) and glycaemic control on risk of cataract in a prospective cohort of Chinese type 2 diabetic patients.

METHODS

The (CA)n microsatellite polymorphism of ALR2 was determined using PCR followed by capillary gel electrophoresis. Cataract was defined by presence of lens opacity on direct ophthalmoscopy or history of cataract surgery. A non-linear curve approach was used to identify the threshold of glycated hemoglobin (HbA1c) at which the odds ratio (OR) for cataract started to increase. The association of z-4 allele with cataract, above and below this threshold, was assessed using multiple logistic regression analysis.

RESULTS

Of the 5823 patients analyzed, 28.1% had cataracts. After adjusting for conventional risk factors and using non-z-4 carriers with HbA1c<8.0% as referent group (n = 3173), the OR (95% confidence intervals) for cataract was highest in z-4 carriers with HbA1c ≥ 8.0% [1.43 (1.05-1.96), n = 244], compared to non-z-4 carriers with HbA1c ≥ 8.0 [1.27 (1.10-1.47), n = 1836] and z-4 carriers with HbA1c<8.0%[1.01 (0.77-1.29), n = 420, P(trend) < 0.001]. This additive association remained significant after additional adjustments for drug use (P(trend) = 0.002) and renal function (P(trend) = 0.01).

CONCLUSIONS

In type 2 diabetic patients with suboptimal glycaemic control, the z-4 allele of ALR2 (CA)n polymorphism was independently associated with increased susceptibility to cataracts.

Glycosylated hemoglobin in relationship to cardiovascular outcomes and death in patients with type 2 diabetes: a systematic review and meta-analysis

Background

Chronic hyperglycemia in type 2 diabetes increases the risk of microvascular events. However, there is continuing uncertainty about its effect on macrovascular outcomes and death. We conducted a meta-analysis of prospective studies to estimate the association of glycosylated hemoglobin level with the risk of all-cause mortality and cardiovascular outcomes among patients with type 2 diabetes.

Methodology/Principal Findings

We systematically searched the MEDLINE database through April 2011 by using Medical Subject Heading search terms and a standardized protocol. We included prospective cohort studies that reported data of glycosylated hemoglobin level on the risk of incident cardiovascular events and all-cause mortality. Relative risk estimates (continuous and categorical variables) were derived or abstracted from each cohort study. Twenty six studies were included in this analysis with a mean follow-up rang of 2.2–16 years. The pooled relative risk associated with a 1% increase in glycosylated hemoglobin level among patients with type 2 diabetes was 1.15 (95% CI, 1.11 to 1.20) for all-cause mortality, 1.17 (95% CI, 1.12 to 1.23) for cardiovascular disease, 1.15 (95% CI, 1.10 to 1.20) for coronary heart disease, 1.11 (95% CI, 1.05 to 1.18) for heart failure, 1.11 (95% CI, 1.06 to 1.17) for stroke, and 1.29 (95% CI, 1.18 to 1.40) for peripheral arterial disease, respectively. In addition, a positive dose-response trend existed between glycosylated hemoglobin level and cardiovascular outcomes.

Conclusions/Significance

Chronic hyperglycemia is associated with an increased risk for cardiovascular outcomes and all-cause mortality among patients with type 2 diabetes, likely independently from other conventional risk factors.

The Complexity of Vascular and Non-Vascular Complications of Diabetes: The Hong Kong Diabetes Registry

Diabetes is a complex disease characterized by chronic hyperglycemia and multiple phenotypes. In 1995, we used a doctor-nurse-clerk team and structured protocol to establish the Hong Kong Diabetes Registry in a quality improvement program. By 2009, we had accrued 2616 clinical events in 9588 Chinese type 2 diabetic patients with a follow-up duration of 6 years. The detailed phenotypes at enrollment and follow-up medications have allowed us to develop a series of risk equations to predict multiple endpoints with high sensitivity and specificity. In this prospective database, we were able to validate findings from clinical trials in real practice, confirm close links between cardiovascular and renal disease, and demonstrate the emerging importance of cancer as a leading cause of death. In addition to serving as a tool for risk stratification and quality assurance, ongoing data analysis of the registry also reveals secular changes in disease patterns and identifies unmet needs.

Low glomerular filtration rate and risk of stroke: meta-analysis

OBJECTIVE

To qualitatively and quantitatively investigate the link between a low estimated glomerular filtration rate (eGFR) at baseline and risk of future stroke.

DESIGN

Systematic review and meta-analysis of prospective studies.

DATA SOURCES

PubMed (1966-October 2009) and Embase (1947-October 2009). Selection criteria Inclusion criteria were studies that prospectively collected data within cohort studies or clinical trials, estimated glomerular filtration rate at baseline using the modification of diet in renal disease or Cockcroft-Gault equations, assessed incident stroke, had a follow-up of at least one year, and reported quantitative estimates of multivariate adjusted relative risk and 95% confidence interval for stroke associated with an eGFR of 60-90 ml/min/1.73 m(2) or <60 ml/min/1.73 m(2). Data abstraction Two investigators independently abstracted data from eligible studies. Estimates were combined using a random effects model. Heterogeneity was assessed by P value of χ(2) statistics and I(2). Publication bias was assessed by visual examination of funnel plots.

RESULTS

21 articles derived from 33 prospective studies: 14 articles assessed eGFR <60 ml/min/1.73 m(2) and seven assessed eGRF at both <60 ml/min/1.73 m(2) and 60-90 ml/min/1.73 m(2) for a total of 284 672 participants (follow-up 3.2-15 years) with 7863 stroke events. Incident stroke risk increased among participants with an eGFR <60 ml/min/1.73 m(2) (relative risk 1.43, 95% confidence interval 1.31 to 1.57; P<0.001) but not among those with an eGFR of 60-90 ml/min/1.73 m(2) (1.07, 0.98 to 1.17; P=0.15). Significant heterogeneity existed between estimates among patients with an eGFR <60 ml/min/1.73 m(2) (P<0.001). In subgroup analyses among participants with an eGFR <60 ml/min/1.73 m(2), heterogeneity was significant in Asians compared with non-Asians (1.96, 1.73 to 2.23 v 1.25, 1.16 to 1.35; P<0.001), and those with an eGFR of 40-60 ml/min/1.73 m(2) v <40 ml/min/1.73 m(2) (1.28, 1.04 to 1.56 v 1.77, 1.32 to 2.38; P<0.01).

CONCLUSIONS

A baseline eGFR <60 ml/min/1.73 m(2) was independently related to incident stroke across a variety of participants and study designs. Prompt and appropriate implementation of established strategies for reduction of vascular risk in people with know renal insufficiency may prevent future strokes.

High birth weight and overweight or obesity among Chinese children 3-6 years old

OBJECTIVE

To investigate the association between different levels of birth weight and the risk of overweight and obesity in children aged 3-6 years.

METHODS

A retrospective longitudinal study of 15,852 children aged 3-6 years in Tianjin, China. Body weight and height, and other factors (age, gestational age, past and current health status, father's and mother's education, occupation and health status, family income, and sex) were obtained using standardized methods.

RESULTS

After adjustment for the above other factors, Chinese children who were born with a birth weight below 2500 g are less likely to become overweight or obese (body mass index more than the 85th percentiles for age and gender specific distribution using the World Health Organization growth reference) during childhood (odd ratio [OR] 0.84, 95% confidence interval [CI] 0.47-1.52) when compared to the reference group (2500-2999 g). However, the odds ratios of becoming overweight or obese during childhood increase significantly when birth weights are 3000-3499 g (OR 1.58, 95% CI 1.33-1.88), 3500-3999 g (OR 2.09, 95% CI 1.76-2.49), and more than 4000 g (OR 3.14, 95% CI 2.60-3.79).

CONCLUSIONS

High levels of birth weight, defined as birth weight >3000 g, were a stronger predictor for overweight and obesity among the Chinese children aged 3-6 years.