Prediction of cardiovascular and total mortality in Chinese type 2 diabetic patients by the WHO definition for the metabolic syndrome

The Association between Metabolic Syndrome and Morbid Events in Type 2 Diabetes after a 7-Year Community Management: Beijing Community Diabetes Study 17

BACKGROUND

To examine the association between morbid events and metabolic syndrome (MS) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A prospective, longitudinal, multicenter study was conducted at 13 community health centers associated with Beijing Tongren Hospital. From 2008 to 2015, there have been 3,525 T2DM patients being managed based on the Chinese guideline for T2DM. The morbid events included macrovascular events, diabetic kidney disease, ophthalmologic events, cancer, and all-cause death.

RESULTS

At baseline, there were 2,708 people with MS and 817 without MS. After a seven-year management, there were 351 (12.96%) events in MS people and 74 (9.06%) events in people without MS (p = 0.003). The prevalence of macrovascular events (6.06%) was much higher in MS people than in people without MS (3.79%, p = 0.013). Cox regression analysis showed an association between MS and morbid events even after adjusting for confounding variables (adjusted hazard ratio = 1.44). MS was also associated with macrovascular events (adjusted hazard ratio = 1.96). The occurrence of morbid events and macrovascular events was increased when the numbers of metabolic abnormalities were 1, 2, 3, and 4 (p < 0.001). There was no continuously statistically significant difference in the cumulative prevalence of morbid events between patients with MS and patients without MS during the first five years. However, after six or seven years, the cumulative prevalence of morbid events in patients with MS was continuously significantly higher than that in patients without MS (11.00% vs. 8.20%, 12.96% vs. 9.06%, p < 0.05).

CONCLUSIONS

T2DM with MS had higher incidence of morbid events, especially cardiovascular events, even after integrated management. The occurrence of morbid and macrovascular events increased as the number of metabolic abnormalities increased. MS was associated with increased risk of morbid events by 44% and macrovascular events by 96%. It would take at least six years to observe the association between MS and morbid events in T2DM.

The Obesity Paradox in Type 2 Diabetes and Mortality

The obesity paradox for survival among individuals with type 2 diabetes has been observed in some but not all studies. Conflicting evidence for the role of overweight and obesity in all-cause mortality may largely be a result of differences in study populations, epidemiological methods, and statistical analysis. For example, analyses among populations with long-term prevalent diabetes and the accrual of other chronic health conditions are more likely to observe that the sickest participants have lower body weights, and therefore, relative to normal weight, overweight and even obesity appear advantageous. Other mortality risk factors, such as smoking, also confound the relationship between body weight and survival, but this behavior varies widely in intensity and duration, making it difficult to assess and effectively adjust for in statistical models. Disentangling the potential sources of bias is imperative in understanding the relevance of excess body weight to mortality in diabetes. In this review, we summarize methodological considerations underlying the observed obesity paradox. Based on the available evidence, we conclude that the obesity paradox is likely an artifact of biases, and once these are accounted for, it is evident that compared with normal body weight, excess body weight is associated with a greater mortality risk.

Dyslipidemia, kidney disease, and cardiovascular disease in diabetic patients

This article reviews the relationship between dyslipidemia, chronic kidney disease, and cardiovascular diseases in patients with diabetes. Diabetes mellitus is associated with complications in the cardiovascular and renal system, and is increasing in prevalence worldwide. Modification of the multifactorial risk factors, in particular dyslipidemia, has been suggested to reduce the rates of diabetes-related complications. Dyslipidemia in diabetes is a condition that includes hypertriglyceridemia, low high-density lipoprotein levels, and increased small and dense low-density lipoprotein particles. This condition is associated with higher cardiovascular risk and mortality in diabetic patients. Current treatment guidelines focus on lowering the low-density lipoprotein cholesterol level; multiple trials have confirmed the cardiovascular benefits of treatment with statins. Chronic kidney disease also contributes to dyslipidemia, and dyslipidemia in turn is related to the occurrence and progression of diabetic nephropathy. Different patterns of dyslipidemia are associated with different stages of diabetic nephropathy. Some trials have shown that treatment with statins not only decreased the risk of cardiovascular events, but also delayed the progression of diabetic nephropathy. However, studies using statins as the sole treatment of hyperlipidemia in patients on dialysis have not shown benefits with respect to cardiovascular risk. Diabetic patients with nephropathy have a higher risk of cardiovascular events than those without nephropathy. The degree of albuminuria and the reduction in estimated glomerular filtration rate are also correlated with the risk of cardiovascular events. Treatment with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers to reduce albuminuria in diabetic patients has been shown to decrease the risk of cardiovascular morbidity and mortality.

Intrarenal arterial resistance is associated with microvascular complications in Chinese type 2 diabetic patients

BACKGROUND

Increased renal arterial resistance is associated with various types of chronic renal parenchymal diseases. A resistance index (RI) > 0.8 predicts deterioration in renal function in diabetic subjects. However, the association between renal RI and other diabetic complications has not been investigated. In this study, we examined the association between intrarenal arterial RI and diabetic complications in Chinese type 2 diabetic subjects.

METHODS

Three hundred and eighty-seven Chinese type 2 diabetic patients were recruited from a structured assessment programme to evaluate their risk factors and complications as a part of the quality improvement programme at the Prince of Wales Hospital. All subjects underwent ultrasound examinations for the assessment of intrarenal arterial RI of both kidneys. Clinical and biochemical parameters, including diabetes-related microvascular complications (nephropathy, retinopathy and sensory neuropathy) and macrovascular diseases, were examined.

RESULTS

The mean RI of patients with any microvascular complications (0.70 ± 0.09 versus 0.65 ± 0.06) such as nephropathy (0.71 ± 0.09 versus 0.66 ± 0.06), retinopathy (0.71 ± 0.08 versus 0.67 ± 0.08) and sensory neuropathy (0.75 ± 0.07 versus 0.68 ± 0.08) and with any macrovascular complications (0.71 ± 0.09 versus 0.68 ± 0.08) was higher than those without (P < 0.05). On multivariate analysis, after controlling for confounding variables, an RI ≥0.75 was associated with microvascular complications, nephropathy, retinopathy and sensory neuropathy, with odds ratio of 4.02 [95% confidence interval (CI) 1.72-9.4], 4.99 (2.61-9.56), 2.78 (1.52-5.09) and 5.74 (1.8-18.3), respectively. The association of RI with macrovascular complications was not significant in multivariate analysis.

CONCLUSION

Increased intrarenal arterial resistance was independently associated with an increased risk of microvascular complications including diabetic nephropathy, diabetic retinopathy and diabetic sensory neuropathy in Chinese type 2 diabetic patients.

Excess risk of mortality and cardiovascular events associated with smoking among patients with diabetes: meta-analysis of observational prospective studies

BACKGROUND

Numerous studies have demonstrated that both smoking and diabetes are risk factors for mortality and caused-specific cardiovascular events. However, few studies systematically investigated to what extent the excess risk could be attributed to smoking among diabetic patients.

METHODS

Literature references were searched up to April 2011 in MEDLINE and EMBASE, supplemented by manual searches. Inclusion criteria were prospective cohort studies, assessment of the association between smoking and total mortality, cardiovascular death, incidence of coronary heart disease (CHD), stroke and myocardial infarction (MI) in diabetic patients.

RESULTS

Of 3758 studies in the literature searched, 46 were eligible with approximately 130,000 diabetic patients. The relative risk (RR) comparing smokers with nonsmokers was 1.48[95% confidential interval (CI): 1.34-1.64] for total mortality (27 studies), 1.36(1.22-1.52) for cardiovascular mortality (9 studies), 1.54(1.31-1.82) for CHD (13 studies), 1.44(1.28-1.61) for stroke (9 studies) and 1.52(1.25-1.83) for MI (7 studies). Furthermore, the excess risk was observed among former and current smokers with a greater risk in current smokers. Subgroup analysis showed that the increased risk appeared to be consistent regardless of several study characteristics with the RRs ranging from 1.31 to 1.94 for all-cause mortality, 1.37 to 2.28 for CHD, 1.21 to 1.87 for stroke, 1.13 to 1.74 for cardiovascular mortality and 1.15 to 2.01 for MI.

CONCLUSION

Smoking amplified the risk of mortality as well as cardiovascular events and the effect size for CHD appeared to be higher than other events in diabetic patients. Moreover, a trend of decreasing risk was observed among smoking quitters.

Components of metabolic syndrome and their combinations as predictors of cardiovascular disease in Japanese patients with type 2 diabetes. Implications for improved definition. Analysis from Japan Diabetes Complications Study (JDCS)

AIM

The prognostic power of metabolic syndrome (MetS) in patients with diabetes has been studied with inconsistent results depending on the definition of MetS. To clarify the best combination of MetS components to predict future cardiovascular disease (CVD) events, we estimated CVD risk in Japanese patients with type 2 diabetes according to MetS components.

METHODS

Patients were categorized according to the presence three MetS components in addition to hyperglycemia. hypertension, dyslipidemia and excess waist circumference (WC) (according to either Japanese or Asian cut-off values). Hazard ratios for CVD events were compared in patients with various categories of MetS components.

RESULTS

At least two components of MetS were required for a significantly elevated risk for CVD; however, component combinations with significantly increased risk differed depending on gender or the WC cut-off value. Any two among 1) excess WC (men > or =90 cm, women > or =80 cm); 2) hypertension (systolic blood pressure > or =130 mmHg or diastolic blood pressure > or =85 mmHg or use of an antihypertensive agent); and 3) dyslipidemia (triglycerides > or =150 mg/dL or HDL-cholesterol <40 mg/dL or use of drug treatment) could be used to identify significantly higher risk (approximately twice) for CVD regardless of gender.

CONCLUSIONS

The results suggest that the current MetS criteria should be modified when applied to patients with type 2 diabetes.

Different accelerators to early-onset Type 2 diabetes: a comparison of Anglo-Celtic and Chinese patients

AIMS

The "accelerator hypothesis" postulates that metabolic syndrome (MS) factors-overweight and insulin resistance-increase functional demand on islets, accelerating diabetes onset to a younger age in both Type 1 and Type 2 diabetes (T2DM). Previous research has focused only on the former. We examine to what extent the MS and individual components are accelerators to the earlier onset of T2DM in Anglo-Celtic and Chinese populations.

METHODS

A cross-sectional study of 1016 Anglo-Celtic and 1514 Chinese patients with recent-onset diabetes (duration <2 years) evaluated over a 12-year period. The MS syndrome and components were analyzed after stratification by age at presentation.

RESULTS

The Anglo-Celtic group shows a high prevalence of MS in early-onset disease and a striking inverse relationship of body mass index (BMI) with age at presentation. For every increase in BMI of 1 kg/m(2), there is a reduction in the age of presentation by 0.5 years (r=-0.3; P<.0001) .Younger groups had a higher prevalence of insulin resistance, elevated triglyceride (Tg), and low high-density lipoprotein cholesterol (HDL-C) (P<.0001 for trend for all three indices). In contrast, the Chinese group showed no relationship between age of presentation with BMI, insulin resistance, Tg, or HDL-C.

CONCLUSIONS

MS factors are important accelerators for T2DM in the Anglo-Celtic but not the Chinese population. This suggests that earlier onset of pancreatic beta cell deficiency is more important as an accelerator of diabetes presentation in Chinese. These data confirm the heterogeneity of T2DM and support the need for more ethnic specific strategies in diabetes prevention.

Expert recommendations on the challenges of hypertension in Asia

A consensus meeting of leading Asian hypertension experts was held in January 2007 in Seoul, Korea, to discuss how to address the growing challenge of hypertension management in the region. This report summarises key recommendations from the group, including: raising public awareness about the impact of hypertension; improving physician education and training; increasing early detection, for example through routine blood pressure measurement; and development and adoption of pan-Asian treatment guidelines, which would greatly facilitate research into hypertension and its management. The group conclude that these challenges can only be met through a collaborative effort of government, healthcare professionals, food and healthcare industries, and patients and the public. Food and healthcare industries need to develop healthy foods and support healthy living programmes, while increasing research into antihypertensive medications in Asia. Government officials and policy makers need to be made aware of the value of investing in hypertension awareness, prevention and management programmes.

Metabolic syndrome in peritoneal dialysis patients

Cardiovascular morbidity and mortality are common in peritoneal dialysis patients. Metabolic syndrome (MES) is a medical condition with a clustering of major risk factors for cardiovascular diseases. In this review article, the various diagnostic criteria used in MES are discussed. It is proposed to use a modified National Cholesterol Education Programme Adult Treatment Panel III (NCEP ATP III) criteria for the diagnosis of MES in peritoneal dialysis (PD) patients taking into consideration the scientific evidence and practicality. When three or more of the following criteria are satisfied in PD patients, obesity, high triglyceride, low high-density lipoprotein cholesterol (HDL-C), hypertension or dysglycaemia, they are diagnosed as having MES. Body mass index (BMI) with reference to ethnicity is suggested to replace waist circumference for diagnosing obesity. Epidemiology and outcome of PD patients with MES are highlighted. The adverse sequelae of obesity appear to be primarily due to fat mass rather than non-fat mass, possibly related to the pro-inflammatory effect of adipose tissue. Whilst there are therapies to tackle MES in PD patients, more conclusive data in human studies to see clinically improved outcomes with such strategies are needed.

Usefulness of microalbuminuria versus the metabolic syndrome as a predictor of cardiovascular disease in women and men>40 years of age (from the Rancho Bernardo Study)

To examine the sex-specific contributions of the metabolic syndrome and microalbuminuria to cardiovascular disease (CVD) and coronary heart disease (CHD) mortality in community-dwelling older adults, 869 women and 575 men aged 40 to 96 years (mean age 71) completed questionnaires, physical examinations, and fasting laboratory tests between 1992 and 1995. Participants were followed over an average of 8 years. CVD and CHD mortality were analyzed using Cox proportional hazards models. At baseline, 267 participants had the Adult Treatment Panel III metabolic syndrome, 151 had microalbuminuria, and 34 had both. During follow-up, there were 180 CVD deaths, including 83 CHD deaths. In women, microalbuminuria was associated with a twofold increased risk of CVD and CHD mortality (p<or=0.01). Women with both microalbuminuria and the metabolic syndrome (n=18) had a threefold increased risk of CVD mortality and a fivefold increased risk of CHD mortality compared with women without either (n=657). A significant interaction existed between microalbuminuria and the metabolic syndrome in the prediction of both CVD and CHD (p=0.02). In men, neither the combination of the metabolic syndrome and microalbuminuria (n=16), nor either alone, significantly increased the risk of CVD or CHD mortality. In conclusion, in this cohort, microalbuminuria and the metabolic syndrome together were a more powerful predictor of CVD mortality than either alone in women but not in men. Screening for microalbuminuria in older women may identify women at high risk for CVD mortality beyond that conferred by risk factors included in the metabolic syndrome.

Effects of albuminuria and renal dysfunction on development of dyslipidaemia in type 2 diabetes--the Hong Kong Diabetes Registry

BACKGROUND

It is uncertain whether albuminuria precedes the future development of high total cholesterol (TC > 6.2 mmol/l) and high LDL-C (>4.1 mmol/l) while renal dysfunction precedes the future development of low HDL-C (<0.9 mmol/l) in type 2 diabetes.

METHODS

A prospective cohort of 2761 type 2 diabetic patients without significant dyslipidaemia and having at least one measurement of TC, LDL-C and HDL-C during 2.8 years of follow-up was analysed. The spline Cox regression model was used to derive hazard ratio (HR) curves of the spot urinary albumin:creatinine ratio (ACR) and the estimated glomerular filtration rate (eGFR) for dyslipidaemia, followed by standard Cox models to confirm the findings from the HR curves.

RESULTS

Seven percent of the cohort developed high TC, 4.6% developed high LDL-C and 5.7% developed low HDL-C during follow-up. In multivariate analysis, the HR of ACR for high TC and high LDL-C increased rapidly and linearly from zero with no apparent threshold. Patients with macroalbuminuria (ACR >/=25 mg/mmol) were, respectively, 1.6- and 2.4 folds more likely to develop high TC and high LDL-C than those with normoalbuminuria at baseline. The HR of eGFR for low HDL-C increased rapidly with declining eGFR at <110 ml/min/ 1.73 m(2). Subjects with eGFR <60 ml/min/1.73 m(2) and >/=60-<110 ml/min/1.73 m(2), respectively, had 3.0-fold and 1.8-fold risks of low HDL-C compared to those with eGFR >/=110-<140 ml/min/1.73 m(2).

CONCLUSIONS

In type 2 diabetes, macroalbumninuria predicts high TC and high LDL-C, while reduced renal function, even within normal range, predicts low HDL-C.

Impacts of chronic kidney disease and albuminuria on associations between coronary heart disease and its traditional risk factors in type 2 diabetic patients - the Hong Kong diabetes registry

Background

Glycated haemoglobin (HbA_1c), blood pressure and body mass index (BMI) are risk factors for albuminuria, the latter in turn can lead to hyperlipidaemia. We used novel statistical analyses to examine how albuminuria and chronic kidney disease (CKD) may influence the effects of other risk factors on coronary heart disease (CHD).

Methods

A prospective cohort of 7067 Chinese type 2 diabetic patients without history of CHD enrolled since 1995 were censored on July 30^th, 2005. Cox proportional hazard regression with restricted cubic spline was used to auto-select predictors. Hazard ratio plots were used to examine the risk of CHD. Based on these plots, non-linear risk factors were categorised and the categorised variables were refitted into various Cox models in a stepwise manner to confirm the findings.

Results

Age, male gender, duration of diabetes, spot urinary albumin: creatinine ratio, estimated glomerular filtration rate, total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and current smoking status were risk factors of CHD. Linear association between TC and CHD was observed only in patients with albuminuria. Although in general, increased HDL-C was associated with decreased risk of CHD, full-range HDL-C was associated with CHD in an A-shaped manner with a zenith at 1.1 mmol/L. Albuminuria and CKD were the main contributors for the paradoxically positive association between HDL-C and CHD for HDL-C values less than 1.1 mmol/L.

Conclusion

In type 2 diabetes, albuminuria plays a linking role between conventional risk factors and CHD. The onset of CKD changes risk associations between lipids and CHD.

Metabolic syndrome and its components as predictors of all-cause mortality and coronary heart disease in type 2 diabetic patients

BACKGROUND

There is no consistent evidence regarding the prognostic value of metabolic syndrome (MS) in predicting all-cause mortality and coronary heart disease (CHD) risk among type 2 diabetic patients. We sought to investigate whether individual or various combinations of MS components have a different predictive value than the presence of MS in this setting.

METHODS

Six hundred type 2 diabetic patients (mean age 60.4+/-9 years, 54% males) without known CHD were prospectively followed-up for a mean period of 10.06 years. The presence of MS was examined using the National Cholesterol Education Program (NCEP) definition. Statistical analyses were performed using Kaplan-Meier estimator and Cox proportional Hazard models.

RESULTS

MS was present in 62.4% of the patients while 142 died during follow-up. Significant predictors for all-cause mortality were the presence of MS (HR 1.75), sex (HR 1.69), age (HR 1.09), and diabetes duration (HR 1.02). Regarding CHD incidents, HDL (HR 0.98), systolic blood pressure (HR 1.01), sex (HR 2.05), and total cholesterol (HR 1.005) were significant predictors while the presence of MS was not. Subjects fulfilling the triad consisting of diabetes, hypertension, and low HDL or the combination of diabetes, hypertension, low HDL, and high triglyceride levels had the highest probability for developing CHD events (HR 1.79, 1.73, respectively).

CONCLUSIONS

The presence of MS in type 2 diabetic patients without known CHD reduces the 10-year survival while specific combinations of its components have different impact on CHD risk.

Prediction of all-cause mortality in a patient population with hypertension and type 2 DM by using traditional risk factors and serum-phosphate,-calcium and-magnesium

The aim of this study is to investigate whether the prediction of all-cause mortality from traditional risk factors is improved by adding electrolytes (serum-phosphate (S-P), serum-calcium (S-Ca) and serum-magnesium (S-Mg)) in a Cox regression. The study uses an 18-year follow-up of patients (n=2504) referred by physicians in primary health care and hospitals to the Vindeln Patient Education (VPE) Center, mainly with a diagnosis of hypertension (HT), type 2 diabetes mellitus (DM) and/or obesity. Cox regression, with the latest registered value and baseline values for risk factors, was used to study all-cause mortality in men and women. 221 out of 1096 men and 157 out of 1408 women died during the 18-year follow-up (20% and 11% respectively). The Cox regression analysis reveals that high blood glucose (B-Glu) and low S-Mg were significantly associated with increased all-cause mortality in the whole patient population as well as in men and women separately. Among women, type 2 DM and systolic blood pressure (SBP) and among men, high S-Ca, S-P, S-urate and body mass index (BMI) were the main predictors of all-cause mortality. There is significantly improved prediction of all-cause mortality with electrolytes added to the traditional risk factors. High B-Glu and low S-Mg in both men and women, and high S-Ca and S-P in men, are significantly associated with all-cause mortality. The metabolic disturbance in this high-risk group of patients can be more fully understood if ionic imbalance is included in the prediction of mortatlity.

Should central obesity be an optional or essential component of the metabolic syndrome? Ischemic heart disease risk in the Singapore Cardiovascular Cohort Study

OBJECTIVE

The International Diabetes Federation (IDF) proposes that central obesity is an "essential" component of the metabolic syndrome, while the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) proposes that central obesity is an "optional" component. This study examines the effect of the metabolic syndrome with and without central obesity in an Asian population with ischemic heart disease (IHD).

RESEARCH DESIGN AND METHODS

From the population-based cohort study (baseline 1992-1995), 4,334 healthy individuals were grouped by the presence or absence of the metabolic syndrome and central obesity and followed up for an average of 9.6 years by linkage with three national registries. Cox's proportional hazards model was used to obtain adjusted hazard ratios (HRs) for risk of a first IHD event.

RESULTS

The prevalence of metabolic syndrome was 17.7% by IDF criteria and 26.2% by AHA/NHLBI criteria using Asian waist circumference cutoff points for central obesity. Asian Indians had higher rates than Chinese and Malays. There were 135 first IHD events. Compared with individuals without metabolic syndrome, those with central obesity/metabolic syndrome and no central obesity/metabolic syndrome were at significantly increased risk of IHD, with adjusted HRs of 2.8 (95% CI 1.8-4.2) and 2.5 (1.5-4.0), respectively.

CONCLUSIONS

Having metabolic syndrome either with or without central obesity confers IHD risk. However, having central obesity as an "optional" rather than "essential" criterion identifies more individuals at risk of IHD in this Asian cohort.