Ethnicity and risk of lower limb amputation in people with Type 2 diabetes: a prospective cohort study.

AIM: Lower limb amputation is a serious complication of diabetic foot disease and there are unexplained ethnic variations in incidence. This study investigates the risk of amputation among different ethnic groups after adjusting for demographic, socio-economic status and clinical variables. METHODS: We used primary care data from a large national multi-ethnic cohort of patients with Type 2 diabetes in New Zealand and linked hospital records. The primary outcome was time from initial data collection to first lower limb amputation. Demographic variables included age of onset and duration since diabetes diagnosis, gender, ethnicity and socio-economic status. Clinical variables included smoking status, height and weight, blood pressure, HbA1c , total cholesterol/HDL ratio and albuminuria. Cox proportional hazards models were used. RESULTS: There were 892 lower limb amputations recorded among 62 002 patients (2.11 amputations per 1000 person-years), followed for a median of 7.14 years (422 357 person-years). After adjusting for demographic and socio-economic variables and compared with Europeans, Maori had the highest risk [hazard ratio (HR) 1.84 (95%CI:1.54-2.19)], whereas East Asians [HR 0.18, (0.08-0.44)] and South Asians [HR 0.39 (0.22-0.67)] had the lowest risk. Adjusting for available clinical variables reduced the differences but they remained substantial [HR 1.61 (1.35-1.93), 0.23 (0.10-0.56) and 0.48 (0.27-0.83), respectively]. CONCLUSIONS: Ethnic groups had significantly different risk of lower limb amputation, even after adjusting for demographic and some major clinical risk factors. Barriers to care should be addressed and intensive prevention strategies known to reduce the incidence of lower limb amputations could be prioritized to those at greatest risk.

The Diabetes Excess Weight Loss (DEWL) Trial: a randomised controlled trial of high-protein versus high-carbohydrate diets over 2 years in type 2 diabetes.

AIMS/HYPOTHESIS: To compare the effectiveness of low-fat high-protein and low-fat high-carbohydrate dietary advice on weight loss, using group-based interventions, among overweight people with type 2 diabetes. Study design Multicentre parallel (1:1) design, blinded randomised controlled trial. METHODS: Individuals with type 2 diabetes aged 30­75 years and a BMI >27 kg/m2 were randomised, by an independent statistician using sequentially numbered sealed envelopes, to be prescribed either a low-fat high-protein (30% of energy as protein, 40% as carbohydrate, 30% as fat) or a low-fat high carbohydrate(15% of energy as protein, 55%as carbohydrate,30% as fat) diet. Participants attended 18 group sessions over 12 months. Primary outcomes were change in weight and waist circumference assessed at baseline, 6 and 12 months.Secondary outcomes were body fatness, glycaemic control,lipid profile, blood pressure and renal function. A further assessment was undertaken 12 months after the intervention.Research assessors remained blinded to group allocation throughout. Intention-to-treat analysis was performed. RESULTS: A total of 419 participants were enrolled (mean±SDage 58±9.5 years,BMI 36.6±6.5 kg/m2 and HbA1c 8.1±1.2%(65 mmol/mol)). The study was completed by 70%(294/419).No differences between groups were found in change in weight or waist circumference during the intervention phase or the 12-month follow-up. Both groups had lost weight (2­3 kg, p<0.001) and reduced their waist circumference (2­3 cm, p<0.001) by 12 months and largely maintained this weight loss for the following 12 months. By 6 months, the difference in self-reported dietary protein between groups was small (1.1%total energy; p<0.001). No significant differences between groups were found in secondary outcomes: body fatness, HbA1c, lipids, blood pressure and renal function.There were no important adverse effects. CONCLUSIONS/INTERPRETATION: In a 'real-world' setting, prescription of an energy-reduced low-fat diet, with either increased protein or carbohydrate, results in similar modest losses in weight and waist circumference over 2 years

Doctors' perceptions of the prognostic benefit of statins in patients who have had myocardial infarction.

BACKGROUND: We wished to assess how General Practitioners (GPs) and cardiologists perceive and communicate the benefits of therapy with statins (hydroxymethylglutaryl-coenzyme A reductase inhibitors) in a patient following myocardial infarction. METHODS: We interviewed 20 GPs and 22 cardiologists to determine treatment policy and ways of expressing its benefits to a patient after myocardial infarction with moderate dyslipidaemia. We asked what drug and dosage they would recommend and how they would express potential benefits of therapy, given a range of options including reduced relative and absolute risk of events. RESULTS: Most GPs would start a low dose (10-20 mg/day) of simvastatin (the only freely prescribable funded statin in New Zealand) whereas cardiologists would commence 40 mg/day immediately (P = 0.001). All but one cardiologist would justify therapy to the patient by citing a reduced chance of a major adverse cardiovascular event. Nine GPs and one cardiologist estimated a gain of more than 5 years of life from statin therapy. Cardiologists were more optimistic than GPs about relative risk reduction (P = 0.04). Only 50% of GPs and 68% of cardiologists were able to estimate an absolute risk reduction over 5 years, such estimates varying widely with no significant difference in responses between the groups (P = 0.2). No doctors felt comfortable using number needed to treat or odds ratio. CONCLUSION: There were substantial differences between the two groups of clinicians in perception and policy of statin therapy, frequent overestimation of treatment benefits and a reluctance to impart numerical estimates of benefit to patients.

Glycated haemoglobin and cardiovascular outcomes in people with Type 2 diabetes: a large prospective cohort study.

AIMS: To investigate the association between long-term glycaemic control, measured by glycated haemoglobin (HbA(1c)), and time to first cardiovascular disease (CVD) event for people with Type 2 diabetes in New Zealand. METHODS: A prospective cohort study including people with Type 2 diabetes but no previous CVD. The primary outcome measure was time to first recorded fatal or non-fatal CVD event (ischaemic heart disease, cerebrovascular accident, transient ischaemic attack or peripheral vascular disease) as identified from linked primary care, hospital and mortality records between January 2000 and December 2005. A Cox proportional hazards model was used to examine the association between HbA(1c) and time to CVD event, adjusting for age at diagnosis, duration of diabetes, gender, ethnicity, socio-economic status, smoking, blood pressure (BP), serum total cholesterol : high-density lipoprotein ratio, body mass index (BMI) and urine albumin : creatinine ratio. RESULTS: Participants included 48 444 people with Type 2 diabetes. Fifty-one per cent (n = 24 721) were women, median age 60 years. Median duration of diabetes was 3 years, median BMI 31 kg/m(2), median HbA(1c) 7.1% and mean BP was 138/81 mmHg. During the study period (median follow-up 2.4 years), there were 5667 first CVD events (11.7% of cohort). Each 1% increase in HbA(1c) was associated with an increase in hazard ratio (HR) for CVD of 1.08 (95% confidence interval 1.06-1.10, P < 0.001), myocardial infarction [HR 1.08 (1.04, 1.11)] and stroke [HR 1.09 (1.04, 1.13)]. CONCLUSION: This study has confirmed in a large prospective cohort that increased HbA(1c) is an independent risk factor for cardiovascular disease after controlling for traditional risk factors.

An association between ethnicity and cardiovascular outcomes for people with Type 2 diabetes in New Zealand.

AIMS: To investigate the association between ethnicity and risk of first cardiovascular (CV) event for people with Type 2 diabetes in New Zealand. METHODS: A prospective cohort study using routinely collected data from a national primary health care diabetes annual review programme linked to national hospital admission and mortality data. Ethnicity was recorded as European, Maori, Pacific, Indo-Asian, East-Asian or Other. A Cox proportional hazards model was used to investigate factors associated with first CV event. Data was collected from 48,444 patients with Type 2 diabetes, with first data collected between 1 January 2000 and 20 December 2005, no previous cardiovascular event at entry and with complete measurements. Risk factors included ethnicity, gender, socio-economic status, body mass index, smoking, age at diagnosis, duration of diabetes, systolic blood pressure, serum lipids, glycated haemoglobin and urine albumin : creatinine ratio. The main outcome measures were time to first fatal or non-fatal CV event. RESULTS: Median follow-up was 2.4 years. Using combined European and Other ethnicities as a reference, hazard ratios for first CV event were 1.30 for Maori (95% confidence interval 1.19-1.41), 1.04 for Pacific (0.95-1.13), 1.06 for Indo-Asian (0.91-1.24) and 0.73 for East-Asian (0.62-0.85) after controlling for all other risk factors. CONCLUSIONS: Ethnicity was independently associated with time to first CV event in people with Type 2 diabetes. Maori were at 30% higher risk of first CV event and East-Asian 27% lower risk compared with European/Other, with no significant difference in risk for Pacific and Indo-Asian peoples.