Trends of clinical parameters and incidences of diabetes mellitus complications among patients with type 2 diabetes mellitus in Hong Kong, 2010–2019: a retrospective cohort study

BACKGROUND: Diabetes mellitus-related characteristics, including available medications, onset ages, and newly-introduced management program, have been changing recently in Hong Kong, especially after the introduction of the Risk Assessment and Management Program–Diabetes Mellitus in all outpatient clinics in 2009. To understand the plural change and improve the management of patients with Type 2 Diabetes Mellitus (T2DM) based on the latest data, we examined the trends of clinical parameters, T2DM complications and mortality in patients with T2DM in Hong Kong from 2010 to 2019. METHODS: In this retrospective cohort study, we acquired data from the Clinical Management System of the Hospital Authority in Hong Kong. Among adults with T2DM diagnosed on or before Sept 30, 2010, and with at least one attendance in general outpatient clinics between Aug 1, 2009, to Sept 30, 2010, we investigated the age-standardised trends of clinical parameters including haemoglobin A1c, systolic blood pressure, diastolic blood pressure, low-density lipoprotein cholesterol (LDL-C), body mass index and estimated glomerular filtration rate (eGFR), complications including cardiovascular disease (CVD), peripheral vascular disease (PVD), sight-threatening diabetic retinopathy (STDR), neuropathy, eGFR<45 mL/min/1.73 m(2) and end-stage renal disease (ESRD), and all-cause mortality from 2010 to 2019 and tested the statistical significance of the trends using generalised estimating equation by sex, level of clinical parameters and age groups. FINDINGS: In total, 82,650 males and 97,734 females with T2DM were identified. LDL-C decreased from 3 to 2 mmol/L in both males and females, while other clinical parameters changed within 5% over the full decade from 2010 to 2019. CVD, PVD, STDR, and neuropathy had declining incidences, while ESRD and all-cause mortality had increasing incidences from 2010 to 2019. The incidence of eGFR<45 mL/min/1.73 m(2) increased in males but decreased in females. The odds ratio (OR) of ESRD (1.13, 95% CI [1.12, 1.15]) was highest in both males and females while the ORs of STDR (0.94, 95% CI [0.92, 0.96]) and neuropathy (0.90, 95% CI [0.88, 0.92]) were lowest in males and females, respectively. Complications and all-cause mortality trends varied among baseline HbA1c, eGFR, and age subgroups. In contrast to the findings in other age groups, the incidence of any outcomes did not decrease in younger patients (<45 years) from 2010 to 2019. INTERPRETATION: Improvements were observed in LDL-C and incidences of most complications from 2010 to 2019. Worse performance in the younger age group and increasing incidence of renal complications and mortality need more attention in managing patients with T2DM. FUNDING: The Health and Medical Research Fund, the Health Bureau, and 10.13039/501100005407Government of the Hong Kong Special Administrative Region.