Relation between HbA1c and incident cardiovascular disease over a period of 6 years in the Hong Kong population.

AIM: The current trend on diabetes management advocates replacing the paradigm from a uniform to an individualized patient-centered haemoglobin A1c (HbA1c) target, but there is no consensus on the optimal HbA1c level. The study aimed at examining the association between HbA1c and the risk of cardiovascular diseases (CVD) for diabetic patients with different characteristics, in order to identify patient-centered treatment targets. METHODS: A retrospective cohort study was conducted on 115,782 Chinese adult primary care patients with type 2 diabetes mellitus (DM) but no known CVD history, who were prescribed antidiabetic medications in 2010-2011. The cumulative mean HbA1c over a median follow-up period of 5.8 years was used to evaluate the relationship between HbA1c and CVD incidence using Cox analysis. Subgroup analyses were conducted by stratifying different baseline characteristics including gender, age, smoking status, diabetes duration, body mass index, Charlson's comorbidity index and DM treatment modalities. RESULTS: For patients with a DM duration of<2years, an exponential relationship between HbA1c and risk of CVD was identified, suggesting that there was no threshold HbA1c level for CVD risk. For other diabetic patients, an HbA1c level of 6.8-7.2% was associated with a minimum risk for CVD and a J-shaped curvilinear association between HbA1c. The risk of CVD increased in patients with HbA1c<6.5% or ≥7.5%. CONCLUSION: Among Chinese primary care patients at the early (<2years) disease stage, lower HbA1c targets (<6.5%) may be warranted to prevent CVD events whilst for all others, excessively lower HbA1c levels may not necessarily better and can potentially be harmful.

Annual direct medical costs associated with diabetes-related complications in the event year and in subsequent years in Hong Kong.

AIM: To develop models to estimate the direct medical costs associated with diabetes-related complications in the event year and in subsequent years. METHODS: The public direct medical costs associated with 13 diabetes-related complications were estimated among a cohort of 128 353 people with diabetes over 5 years. Private direct medical costs were estimated from a cross-sectional survey among 1825 people with diabetes. We used panel data regression with fixed effects to investigate the impact of each complication on direct medical costs in the event year and subsequent years, adjusting for age and co-existing complications. RESULTS: The expected annual public direct medical cost for the baseline case was US$1,521 (95% CI 1,518 to 1,525) or a 65-year-old person with diabetes without complications. A new lower limb ulcer was associated with the biggest increase, with a multiplier of 9.38 (95% CI 8.49 to 10.37). New end-stage renal disease and stroke increased the annual medical cost by 5.23 (95% CI 4.70 to 5.82) and 5.94 (95% CI 5.79 to 6.10) times, respectively. History of acute myocardial infarction, congestive heart failure, stroke, end-stage renal disease and lower limb ulcer increased the cost by 2-3 times. The expected annual private direct medical cost of the baseline case was US$187 (95% CI 135 to 258) for a 65-year-old man without complications. Heart disease, stroke, sight-threatening diabetic retinopathy and end-stage renal disease increased the private medical costs by 1.5 to 2.5 times. CONCLUSIONS: Wide variations in direct medical cost in event year and subsequent years across different major complications were observed. Input of these data would be essential for economic evaluations of diabetes management programmes.

Effectiveness of the multidisciplinary Risk Assessment and Management Program for Patients with Diabetes Mellitus (RAMP-DM) for diabetic microvascular complications: A population-based cohort study.

AIM: To evaluate the effectiveness of the multidisciplinary Risk Assessment and Management Program for Patients with Diabetes Mellitus (RAMP-DM) in reducing the risks of microvascular complications. METHODS: This prospective cohort study was conducted with 29,670 propensity-score-matched RAMP-DM participants and diabetes patients under the usual primary care (14,835 in each group). Study endpoints were the first occurrence of any diabetic microvascular complications, non-proliferative diabetic retinopathy/preproliferative diabetic retinopathy (NPDR/prePDR), sight-threatening diabetic retinopathy (STDR) or blindness, nephropathy, end-stage renal disease (ESRD), neuropathy and lower-limb ulcers or amputation. Log-rank tests and multivariable Cox proportional-hazards regressions were employed to estimate between-group differences in incidences of study endpoints. RESULTS: After a median follow-up of 36 months with>41,000 person-years in each group, RAMP-DM participants had a lower incidence of microvascular complications (760 vs 935; adjusted hazard ratio [HR]: 0.73; 95% confidence interval [CI]: 0.66-0.81; P<0.001) and lower incidences of all specific microvascular complications except neuropathy (adjusted HR: 0.94; 95% CI: 0.61-1.45; P=0.778). Adjusted HRs for the RAMP-DM vs control group for ESRD, STDR or blindness, and lower-limb ulcers or amputation were 0.40 (95% CI: 0.24-0.69; P<0.001), 0.55 (95% CI: 0.39-0.78; P=0.001) and 0.49 (95% CI: 0.30-0.80; P=0.005), respectively. CONCLUSION: The RAMP-DM intervention was associated with lower incidences of all microvascular complications except neuropathy over a 3-year follow-up. These encouraging results constitute evidence that structured risk assessment and risk-stratified management provided by a multidisciplinary team is effective for reducing microvascular complications in diabetes patients. CLINICAL TRIAL REGISTRY: NCT02034695, www.ClinicalTrials.gov.