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Juliana C N Chan

Publications and source records attributed to Juliana C N Chan.

At least 19 recordsLinked to original sources
PubMed2026

A narrative review of what cohorts have taught us and how they have laid the foundation for much of our understanding of type 2 diabetes.

This narrative review provides a historical perspective on how observational research on type 2 diabetes has been developed and consolidated over the last 50 years and how well-designed cohort studies will provide us with knowledge for research and practice in the future and aid guideline development. We have included data from a large number of cohorts from every continent that have been used to study the development and/or progression of type 2 diabetes, including cohorts that are general population-based, disease-based, intervention-based and registry-based. We have structured the results from the past 50 years based on the following themes: diagnosis and screening, complications, risk factors and pathophysiology. We also discuss the strengths and weaknesses of observational research when compared with other research designs. Finally, we discuss the emerging and future directions for type 2 diabetes research using cohorts, which include novel developments, such as artificial intelligence, precision health and the exposome. We conclude that cohort research has significantly advanced our understanding of type 2 diabetes and aided guideline development, and complements experimental work, such as human randomised controlled trials and animal studies. Both approaches are essential and complementary in our pursuit to provide a more comprehensive understanding of the development and progression of type 2 diabetes, and to change dogma, practice and policies for better outcomes.

Humans↗
PubMed2007

Bayesian analysis of structural equation models with multinomial variables and an application to type 2 diabetic nephropathy.

There is now increasing evidence proving that many complex diseases can be significantly influenced by correlated phenotype and genotype variables, as well as their interactions. Effective and rigorous assessment of such influence is difficult, because the number of phenotype and genotype variables of interest may not be small, and a genotype variable is an unordered categorical variable that follows a multinomial distribution. To address the problem, we establish a novel nonlinear structural equation model for analysing mixed continuous and multinomial data that can be missing at random. A confirmatory factor analysis model with Kronecker product is proposed for grouping the manifest continuous and multinomial variables into latent variables according to their functions; and a nonlinear structural equation is formulated to assess the linear and interaction effects of the independent latent variables to the dependent latent variables. Bayesian methods for estimation and model comparison are developed through Markov chain Monte Carlo techniques and path sampling. The newly developed methodologies are applied to a case-control cohort of type 2 diabetic patients with nephropathy.

Bayes Theorem↗
PubMed2007

Effects of chronic hyperglycaemia on incident stroke in Hong Kong Chinese patients with type 2 diabetes.

BACKGROUND: It remains unclear whether hyperglycaemia as measured by HbA(1c) is a significant risk factor for stroke in patients with type 2 diabetes mellitus (T2DM). METHODS: A case-control study nested in a prospective cohort with 1 : 3 controls matched on age, gender, systolic blood pressure and low-density lipoprotein cholesterol (LDL-C) was conducted. The case group included 105 patients who developed incident stroke during 2.88 years (SD: 1.59) of follow-up of 4150 T2DM patients and 299 matched patients without incident stroke, used as the control group. Stratified Cox proportional hazard regression was used to obtain hazard ratio (HR). RESULTS: Median age was 71 years (IQR: 9.0 for the case and 10.0 for the control). HbA(1c) was significantly higher in the cases than in the controls (median 8.0% [IQR: 2.0] versus 7.2% [2.1], p < 0.0001). After controlling for smoker status, haematocrit, drug treatments and other covariates, 1% increase in HbA(1c) was associated with 1.49 (95% CI: 1.18-1.88, p = 0.0008) folds risk of occurrence of incident stroke. Patients with a history of coronary heart disease (CHD) were also at increased risk of stroke (HR: 8.25, 95% CI: 2.22-30.73, p = 0.0016). Smoker status and haematocrit were marginally significant predictors of incident stroke. Every adjusted month using lipid-lowering drugs was significantly associated with reduced risk of incident stroke (HR: 0.95, 95% CI: 0.90-0.99, p = 0.0199). Similar analysis using ACEI or ARB as a drug group was marginally significant (p = 0.0555). CONCLUSION: Chronic hyperglycaemia is a risk factor of stroke in Chinese patients with T2DM.

Aged↗
PubMed2007

Development and validation of stroke risk equation for Hong Kong Chinese patients with type 2 diabetes: the Hong Kong Diabetes Registry.

OBJECTIVE: We sought to develop stroke risk equations for Chinese patients with type 2 diabetes in Hong Kong. RESEARCH DESIGN AND METHODS: A total of 7,209 Hong Kong Chinese type 2 diabetic patients without a history of stroke at baseline were analyzed. The data were randomly and evenly divided into the training subsample and the test subsample. In the training subsample, stepwise Cox models were used to develop the risk equation. Validation of the U.K. Prospective Diabetes Study (UKPDS) stroke risk engine and the current stroke equation was performed in the test dataset. The life-table method was used to check calibration, and the area under the receiver operating characteristic curve (aROC) was used to check discrimination. RESULTS: A total of 372 patients developed incident stroke during a median of 5.37 years (interquartile range 2.88-7.78) of follow-up. Age, A1C, spot urine albumin-to-creatinine ratio (ACR), and history of coronary heart disease (CHD) were independent predictors. The performance of the UKPDS stroke engine was suboptimal in our cohort. The newly developed risk equation defined by these four predictors had adequate performance in the test subsample. The predicted stroke-free probability by the current equation was within the 95% CI of the observed probability. The aROC was 0.77 for predicting stroke within 5 years. The risk score was computed as follows: 0.0634 x age (years) + 0.0897 x A1C + 0.5314 x log(10) (ACR) (mg/mmol) + 0.5636 x history of CHD (1 if yes). The 5-year stroke probability can be calculated by: 1 - 0.9707(EXP (Risk Score - 4.5674)). CONCLUSIONS: Although the risk equation performed reasonably well in Chinese type 2 diabetic patients, external validation is required in other populations.

Asian People↗
PubMed2006

Overweight, family history of diabetes and attending schools of lower academic grading are independent predictors for metabolic syndrome in Hong Kong Chinese adolescents.

BACKGROUND: Overweight and metabolic syndrome (MES) are emerging in both adult and paediatric populations. AIMS: To study the prevalence of and associated risk factors for the MES, using the National Cholesterol Education Program definition, among Hong Kong Chinese adolescents studying in secondary schools. METHODS: This was a cross-sectional, population-based study. A sample of 2115 Chinese adolescents was randomly selected from 14 secondary schools throughout Hong Kong. Data on anthropometric parameters, fasting blood and urine samples were collected in the school setting. Information regarding the adolescent's family history of diabetes, perinatal history, socioeconomic status and school grading was evaluated. RESULTS: The prevalence of MES was 2.4% (95% confidence interval (CI) 1.8 to 3.1), with no significant difference between boys (2.9%) and girls (2%). The prevalence of various components of MES was 32.2% (30.2 to 34.2) for hypertension, 10.9% (9.6 to 12.2) for increased triglyceride, 9.0% (7.8 to 10.2) for central adiposity, 2.4% (1.7 to 3) for low high-density lipoprotein cholesterol and 0.3% (0.1 to 0.6) for impaired fasting glucose. On multivariate analysis, overweight (odds ratio 32.2; 95% CI 13.2 to 78.4), positive family history of diabetes (4.3; 1.3 to 14.1) and studying at schools of lower academic grading (5.5; 2.2 to 13.7) were found to be independent risk factors for MES. CONCLUSION: A comparable prevalence of MES (2%) is observed in our study group Chinese adolescent girls and in US girls (2.1%), but a lower prevalence in Chinese boys (2.9%) than in US boys (6.1%). In our study, 41.8% harbour at least one component of the syndrome. Both families and schools should be alerted to this growing epidemic.

Adolescent↗
PubMed2006

Effectiveness of telephone counselling by a pharmacist in reducing mortality in patients receiving polypharmacy: randomised controlled trial.

OBJECTIVE: To investigate the effects of compliance and periodic telephone counselling by a pharmacist on mortality in patients receiving polypharmacy. DESIGN: Two year randomised controlled trial. SETTING: Hospital medical clinic. PARTICIPANTS: 502 of 1011 patients receiving five or more drugs for chronic disease found to be non-compliant at the screening visit were invited for randomisation to either the telephone counselling group (n = 219) or control group (n = 223) at enrollment 12-16 weeks later. MAIN OUTCOME MEASURES: Primary outcome was all cause mortality in randomised patients. Associations between compliance and mortality in the entire cohort of 1011 patients were also examined. Patients were defined as compliant with a drug if they took 80-120% of the prescribed daily dose. To calculate a compliance score for the whole treatment regimen, the number of drugs that the patient was fully compliant with was divided by the total number of prescribed drugs and expressed as a percentage. Only patients who complied with all recommended drugs were considered compliant (100% score). RESULTS: 60 of the 502 eligible patients defaulted and only 442 patients were randomised. After two years, 31 (52%) of the defaulters had died, 38 (17%) of the control group had died, and 25 (11%) of the intervention group had died. After adjustment for confounders, telephone counselling was associated with a 41% reduction in the risk of death (relative risk 0.59, 95% confidence interval 0.35 to 0.97; P = 0.039). The number needed to treat to prevent one death at two years was 16. Other predictors included old age, living alone, rate of admission to hospital, compliance score, number of drugs for chronic disease, and non-treatment with lipid lowering drugs at screening visit. In the cohort of 1011 patients, the adjusted relative risk for death was 1.61 (1.05 to 2.48; P = 0.029) and 2.87 (1.80 to 2.57; P < 0.001) in patients with compliance scores of 34-66% and 0-33%, respectively, compared with those who had a compliance score of 67% or more. CONCLUSION: In patients receiving polypharmacy, poor compliance was associated with increased mortality. Periodic telephone counselling by a pharmacist improved compliance and reduced mortality. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number Register: SRCTN48076318.

Adult↗
PubMed2006

Role of metformin in the initiation of pharmacotherapy for type 2 diabetes: an Asian-Pacific perspective.

Increases in the prevalence of type 2 diabetes of 30-60% will occur in many Asian-Pacific countries by 2025, driven by urbanisation, sedentary habits and energy-rich diets. Obesity, insulin resistance, metabolic syndrome and diabetes are closely interrelated. Optimal control of diabetes and associated risk factors has reduced the risk of diabetes-related complications. In the UK Prospective Diabetes Study (UKPDS), metformin reduced the risk of macrovascular complications and retrospective analyses have confirmed the efficacy of metformin in improving clinical outcomes in type 2 diabetic patients with a history of cardiovascular disease. This growing body of evidence has led to the recommendation of metformin as optimum initial pharmacotherapy in overweight type 2 diabetic patients. Obesity is less prevalent in the Asian-Pacific population than in Caucasian populations. Nevertheless, metformin has multiple beneficial metabolic effects, which provide sufficient rationale for it to be recommended as the initial oral anti-diabetic pharmacotherapy, alone or in combination, irrespective of body mass index. This recommendation is consistent with global guidelines and regional recommendations for the Asian-Pacific region from the International Diabetes Federation. These recommendations can serve as templates for development of local guidelines for Asian people with diabetes, given the ethnic and cultural diversity within the region.

Asia↗
PubMed2006

Protein kinase Czeta mediates insulin-induced glucose transport through actin remodeling in L6 muscle cells.

Protein kinase C (PKC) zeta has been implicated in insulin-induced glucose uptake in skeletal muscle cell, although the underlying mechanism remains unknown. In this study, we investigated the effect of PKCzeta on actin remodeling and glucose transport in differentiated rat L6 muscle cells expressing myc-tagged glucose transporter 4 (GLUT4). On insulin stimulation, PKCzeta translocated from low-density microsomes to plasma membrane accompanied by increase in GLUT4 translocation and glucose uptake. Z-scan confocal microscopy revealed a spatial colocalization of relocated PKCzeta with the small GTPase Rac-1, actin, and GLUT4 after insulin stimulation. The insulin-mediated colocalization, PKCzeta distribution, GLUT4 translocation, and glucose uptake were inhibited by wortmannin and cell-permeable PKCzeta pseudosubstrate peptide. In stable transfected cells, overexpression of PKCzeta caused an insulin-like effect on actin remodeling accompanied by a 2.1-fold increase in GLUT4 translocation and 1.7-fold increase in glucose uptake in the absence of insulin. The effects of PKCzeta overexpression were abolished by cell-permeable PKCzeta pseudosubstrate peptide, but not wortmannin. Transient transfection of constitutively active Rac-1 recruited PKCzeta to new structures resembling actin remodeling, whereas dominant negative Rac-1 prevented the insulin-mediated PKCzeta translocation. Together, these results suggest that PKCzeta mediates insulin effect on glucose transport through actin remodeling in muscle cells.

Actins↗
PubMed2006

Renin angiotensin aldosterone system blockade and renal disease in patients with type 2 diabetes: a subanalysis of Japanese patients from the RENAAL study.

BACKGROUND: The Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study has previously shown losartan to confer significant benefits to patients with type 2 diabetes and nephropathy. The original study of 1513 patients included 96 Japanese patients; the present study is a post-hoc analysis of the effects of losartan in this Japanese subpopulation. METHODS: This double-blind, randomized study compared losartan (50 to 100 mg once daily) with placebo. The study medication was taken in addition to conventional antihypertensive treatment, and the mean follow-up period for the Japanese patients was 2.8 years. The primary endpoint was the composite of doubling of serum creatinine, endstage renal disease, or death. Secondary endpoints included changes in proteinuria levels. Safety was also evaluated. RESULTS: The primary composite endpoint was reached in fewer Japanese patients receiving losartan than placebo (50.0% versus 65.4%, respectively). The treatment effects of losartan were more robust when data were corrected for differences in proteinuria at baseline--a significant relative risk reduction of 45% with losartan (P=0.0397) was apparent. Treatment benefit exceeded that attributable to blood pressure changes alone. Levels of proteinuria were reduced with losartan compared with placebo, with an overall losartan treatment effect of 37.8% (P<0.001). Overall, losartan was similarly well tolerated in both the Japanese patients and the total population. CONCLUSIONS: In Japanese patients with type 2 diabetes and nephropathy, losartan offers renal protection and is generally well tolerated.

Adult↗
PubMed2006

Traditional Chinese medicine in the treatment of diabetes.

This review focuses on the efficacy and safety of Chinese medicine in the treatment of type-2 diabetes. Included were 84 controlled clinical studies of type-2 diabetes treated with Chinese medicine for at least 1 month. Reported outcomes were: symptom relief; improvement in glycemia, insulin resistance and secondary failure, and adverse events. Symptom relief was achieved in most (>80%) of the patients receiving Chinese medicine. Compared with orthodox drugs, Chinese medicine had a 1.2-fold (95% CI 1.2-1.3) increase in symptom relief. The relative risk of achieving a fasting blood glucose of <7.3 mmol/l or a postprandial blood glucose of <8.2 mmol/l was: 3.0 (95% CI 1.4-6.5) for Chinese medicine plus diet versus diet; 2.0 (95% CI 1.4-3.0) for Chinese medicine versus placebo; 1.8 (95% CI 1.4-2.3) for combined Chinese medicine and orthodox drugs versus Yuquan Wan (a classic Chinese herbal formula for diabetes), 1.5 (95% CI 1.4-1.7) for combined Chinese medicine and orthodox drugs vs. orthodox drugs, and 1.3 (95% CI 1.2-1.5) for Chinese medicine versus orthodox drugs. A fasting blood glucose of <8.2 mmol/l plus symptom relief was observed in 71-100% of the patients with secondary failure to oral anti-diabetic drugs. Serious adverse events including hypoglycemic coma and death were caused by adulteration with orthodox drugs, erroneous substitution, self-meditation, overdoses, and improper preparation. Chinese herbal medicine should be used cautiously with doctors' prescription and follow-up. Long-term clinical studies may disclose the effectiveness of Chinese medicine in reducing the mortality and morbidity of diabetic complications.

Blood Glucose↗
PubMed2006

Variation within the gene encoding the upstream stimulatory factor 1 does not influence susceptibility to type 2 diabetes in samples from populations with replicated evidence of linkage to chromosome 1q.

The gene encoding the transcription factor upstream stimulatory factor (USF)1 influences susceptibility to familial combined hyperlipidemia (FCHL) and triglyceride levels. Phenotypic overlap between FCHL and type 2 diabetes makes USF1 a compelling positional candidate for the widely replicated type 2 diabetes linkage signal on chromosome 1q. We typed 22 variants in the F11R/USF1 region (1 per 3 kb), including those previously implicated in FCHL-susceptibility (or proxies thereof) in 3,726 samples preferentially enriched for 1q linkage. We also examined glucose- and lipid-related continuous traits in an overlapping set of 1,215 subjects of European descent. There was no convincing evidence for association with type 2 diabetes in any of seven case-control comparisons, individually or combined. Family-based association analyses in 832 Pima subjects were similarly negative. At rs3737787 (the variant most strongly associated with FCHL), the combined odds ratio, per copy of the rarer A-allele, was 1.10 (95% CI 0.97-1.24, P = 0.13). In 124 Utah subjects, rs3737787 was significantly associated (P = 0.002) with triglyceride levels, but direction of this association was opposite to previous reports, and there was no corroboration in three other samples. These data exclude USF1 as a major contributor to type 2 diabetes susceptibility and the basis for the chromosome 1q linkage. They reveal only limited evidence for replication of USF1 effects on continuous metabolic traits.

Adult↗
PubMed2006

Glomerular filtration rate, cardiorenal end points, and all-cause mortality in type 2 diabetic patients.

OBJECTIVE: Chronic kidney disease (CKD) predicts cardiovascular disease (CVD) in the general population. We investigated the effects of stages of renal function using the estimated glomerular filtration rate (eGFR) on all-cause mortality and cardiovascular end points in a prospective cohort of Chinese type 2 diabetic patients. RESEARCH DESIGN AND METHODS: Between 1995 and 2000, 4,421 patients without macrovascular disease or end-stage renal disease were recruited. Renal function was assessed by eGFR, as calculated by the abbreviated Modification of Diet in Renal Disease Study Group formula. Clinical end points included all-cause mortality, cardiovascular end point (cardiovascular death, new admissions due to angina, myocardial infarction, stroke, revascularization, or heart failure), and renal end point (reduction in eGFR by >50%, progression of eGFR to stage 5, or dialysis or renal death). RESULTS: After a median follow-up period of 39.4 months (interquartile range 20.3-55), all-cause mortality rate increased from 1.2% (95% CI 0.8-1.7) to 18.3% (9.1-27.5) (P for trend <0.001) as renal function deteriorated from stage 1 (eGFR > or =90 ml/min per 1.73 m(2)) to stage 4 (15-29 ml/min per 1.73 m(2)). The respective rate of new cardiovascular end points also increased from 2.6% (2.0-3.3) to 25.3% (15.0-35.7) (P for trend <0.001). After adjustment for covariates (age, sex, albuminuria, use of renin-angiotensin-aldosterone system [RAAS] inhibitors, lipids, blood pressure, and glycemic control), hazard ratios across different stages of eGFR (> or =90, 60-89, 30-59, and 15-29 ml/min per 1.73 m(2)) for all-cause mortality were 1.00, 1.27, 2.34, and 9.82 (P for trend <0.001), for cardiovascular end points were 1.00, 1.04, 1.05, and 3.23 (P for trend <0.001), and for renal end points were 1.00, 1.36, 3.34, and 27.3 (P for trend <0.001), respectively. CONCLUSIONS: Chinese type 2 diabetic patients with reduced eGFR were at high risk of developing cardiovascular end points and all-cause mortality, independent of albuminuria and metabolic control.

Adult↗
PubMed2006

Hematocrit, independent of chronic kidney disease, predicts adverse cardiovascular outcomes in chinese patients with type 2 diabetes.

OBJECTIVE: Anemia and chronic kidney disease (CKD) are risk factors for cardiovascular diseases in diabetes. We examined the association between hematocrit, stratified by the presence of CKD, and cardiovascular events in a cohort of Chinese subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 3,983 patients who underwent assessment for diabetes complications were recruited. Subjects were categorized into five groups. Group I included subjects with hematocrit below the normal sex-specific range. The cutoff points for groups II-V were selected to represent the distribution of the hematocrit for each sex. CKD was defined by the estimated glomerular filtration rate <60 ml/min per 1.73 m(2). Cardiovascular events were defined as cardiovascular mortality and morbidity, including new onset of myocardial infarction, acute coronary syndrome, revascularization, heart failure, and stroke requiring hospitalization. RESULTS: A total of 294 subjects (7.4%) developed cardiovascular events during the median of 36.4 months. The rate of cardiovascular events was highest in subjects with low hematocrit (group I, 18.6%) compared with group V (3.4%, P < 0.001). The multivariate-adjusted hazard ratio for cardiovascular events diminished with increasing hematocrit (group I, 1.0; group II, 0.73 [95% CI 0.51-1.04]; group III, 0.57 [0.39-0.83]; group IV, 0.61 [0.39-0.95]; and group V, 0.36 [0.17-0.79]). After stratifying by the presence of CKD, the previously observed reduction in the risk of developing cardiovascular events with increasing hematocrit was abolished in the cohort with CKD but persisted in the non-CKD cohort. CONCLUSIONS: In Chinese subjects with type 2 diabetes, low levels of hematocrit and the presence of CKD are associated with increased risk of developing adverse cardiovascular events.

Adult↗
PubMed2005

Association of testosterone, insulin-like growth factor-I, and C-reactive protein with metabolic syndrome in Chinese middle-aged men with a family history of type 2 diabetes.

CONTEXT: Age-related declines in testosterone and IGF-I are associated with deposition of visceral fat, a component of the metabolic syndrome (MES). OBJECTIVE: Testosterone and IGF-I may interact with familial disposition to diabetes mellitus to increase the association with MES. DESIGN: We conducted a cross-sectional cohort study. SETTING: The study was conducted in a university teaching hospital. SUBJECTS: Study subjects included 179 middle-aged men with a family history of diabetes (FH) (aged 39.1 +/- 8.1 yr) and 128 men without FH (aged 43.8 +/- 8.5 yr). MAIN OUTCOME MEASURES: Clinical characteristics, frequency of MES using the World Health Organization criteria with Asian definitions of obesity (body mass index > or = 25 kg/m2), and serum levels of total testosterone, IGF-I, and high-sensitive C-reactive protein (hs-CRP) were measured. RESULTS: Men with FH had higher frequency of MES than those without FH [39.1 vs. 23.4% (P = 0.004)]. On multivariate analysis, smoking (former and current smokers), low total testosterone, and IGF-I but elevated hs-CRP levels explained 35% of the MES variance in men with FH. The frequency of MES increased with declining tertiles of total testosterone and IGF-I but increasing tertiles of hs-CRP. After adjustment for age and smoking history, subjects with all three risk factors had a 13-fold increase in risk association with MES compared with those without hormonal and inflammatory risk factors. These risk associations were not found in men without FH in whom only smoking (ex and current) and low total testosterone level were independent predictors for MES, which explained 14% of the variance. CONCLUSIONS: Clustering of FH, hormonal abnormalities, and high hs-CRP is associated with MES in Chinese middle-aged men.

Adult↗
PubMed2005

In vivo treatment with glucagon-like peptide 1 promotes the graft function of fetal islet-like cell clusters in transplanted mice.

Fetal pancreatic tissue has been suggested as a possible cell source for islet replacement therapy in type 1 diabetes mellitus. This tissue consists of a small amount of beta-cells, but a raft of immature and/or progenitor cells which nonetheless have the potential to proliferate and differentiate into functional insulin-producing cells. Freshly isolated fetal islet-like cell clusters are poorly responsive to glucose challenge, compared with adult islets. Upon exposure to appropriate growth factors and microenvironments, both the expansion and differentiation of fetal islet-like cell clusters can be enhanced. In this study, we investigated the role of exendin-4, a long-acting analogue of glucagon-like peptide 1 in the promotion of functional maturation of transplanted fetal islet-like cell clusters in vivo. Both blood glucose levels and body weights of transplanted diabetic mice treated with exendin-4 improved significantly compared with the transplanted group not subjected to exendin-4 treatment during the 3-month post-transplantation period. In addition, blood glucose levels on formal glucose challenge were also significantly improved by the end of the experiments. In the exendin-4-treated group, there were revascularization and insulin-producing cells as evidenced by positive immunostaining of the Lectins Bandeiraea simplicifolia and insulin, respectively, in the graft bearing kidney. These data indicate that in vivo exendin-4 treatment may enhance the growth and differentiation of fetal mice islet-like cell clusters, thus promoting the functional maturation of the graft after transplantation.

Animals↗
PubMed2005

Association between tumour necrosis factor-alpha G-308A polymorphism and risk of nephropathy in obese Chinese type 2 diabetic patients.

BACKGROUND: The G-308A polymorphism in the promoter region of the tumor necrosis factor alpha (TNF-alpha) gene has been reported to be associated with insulin resistance and obesity, both of which may increase the risk of diabetic nephropathy. We hypothesized that this polymorphism might interact with obesity to affect development of diabetic nephropathy. METHODS: A consecutive cohort of 1281 Chinese type 2 diabetic patients was enrolled for analysis. Genotyping of TNF-alpha G-308A polymorphism was performed using a PCR-based RFLP method with NcoI digestion. The mean value of the albumin creatinine ratio (ACR) of a random spot urine sample and a timed urinary collection was used to determine albuminuric status. Diabetic nephropathy was defined as serum creatinine > or =150 micromol/L and/or mean ACR > or =25 mg/mmol. Obesity was defined as body mass index > or =25 kg/m2 using Asian criteria. RESULTS: The G-308A polymorphism was not associated with either obesity or nephropathy. Clinical characteristics were similar between GG and GA/AA genotype carriers. Amongst the obese patients, GG genotype carriers had a higher median (interquartile range) urinary ACR [3.16 (0.70, 59.10) vs 1.28 (0.48, 12.28) mg/mmol; p = 0.01] and albumin excretion rate [38.7 (12.1, 620.3) vs 21.4 (8.9, 224.0) microg/min, p = 0.03] than GA/AA carriers. On multiple logistic regression analysis, compared with non-obese GA/AA carriers, obese subjects with the GG genotype had a 2.5-fold increased risk (95% CI: 1.04-6.03; P = 0.04) of nephropathy after adjustment for confounding factors. Other independent factors for diabetic nephropathy included male sex, systolic blood pressure, triglycerides (logarithmically transformed value), and the presence of cardiovascular and microvascular complications. CONCLUSION: Our findings suggest that the GG genotype of TNF-alpha G-308A polymorphism or a genetic variant in close linkage disequilibrium may interact with obesity to increase the risk of nephropathy in Chinese Type 2 diabetic patients. Apart from the need for replication of these results, functional studies are required to clarify its significance.

Aged↗