BACKGROUND: The prevalence and incidence of type 1 diabetes mellitus (T1DM) in all age groups and the prevalence of metabolic syndrome in patients with T1DM in Korea were estimated. METHODS: The incidence and prevalence of T1DM between 2007 and 2013 were calculated using the Korean National Health Insurance Service (NHIS) datasets of claims. Clinical characteristics and prevalence of metabolic syndrome in individuals with T1DM between 2009 and 2013 were determined using the database of NHIS preventive health checkups. RESULTS: The prevalence of T1DM in Korea between 2007 and 2013 was 0.041% to 0.047%. The annual incidence rate of T1DM in Korea in 2007 to 2013 was 2.73 to 5.02/100,000 people. Although the incidence rate of typical T1DM was highest in teenagers, it remained steady in adults over 30 years of age. In contrast, the incidence rate of atypical T1DM in 2013 was higher in people aged 40 years or older than in younger age groups. Age- and sex-adjusted prevalence of metabolic syndrome in patients with T1DM was 51.65% to 55.06% between 2009 and 2013. CONCLUSION: T1DM may be more common in Korean adults than previously believed. Metabolic syndrome may be a frequent finding in individuals with T1DM in Korea.
Adolescent ; Adult ; Dataset ; Diabetes Mellitus, Type 1 ; Humans ; Incidence ; Korea ; National Health Programs ; Prevalence

Objective: We investigated the effects of statin-ezetimibe combination therapy compared with statin-only treatment on the hazard of incident type 2 diabetes (T2D), myocardial infarction (MI), and stroke among adults with impaired fasting glucose (IFG) in a real-world setting. Methods: The Korean National Health Insurance Service datasets from 2002 to 2017 were used for this propensity-matched nationwide cohort study. Among 56,633 IFG patients without baseline cardiovascular disease (CVD) and/or T2D who initiated statin therapy with or without ezetimibe, 1,155 with statin-ezetimibe combination therapy were matched based on a propensity score at a 1:5 ratio with 5,775 patients who received statin monotherapy. The hazards of T2D, MI, and stroke were compared between these treatment groups. Results: The incidence rate per 1,000 person-years was 19.62 (statin monotherapy group) and 21.02 (combined treatment group) for T2D, 1.53 (statin monotherapy group) and 1.70 (combined treatment group) for MI, and 1.99 (statin monotherapy group) and 2.06 (combined treatment group) for stroke. The hazards of T2D, MI, and stroke were not significantly different between the statin monotherapy group and the statin-ezetimibe combination therapy group. Conclusion The combination of ezetimibe in addition to statin treatment was not associated with a significantly different risk of T2D and CVDs compared with statin monotherapy in Korean adults with IFG.

Background: We explored the risk of death from pneumonia according to cumulative duration in low household income state (LHIS) among adults with type 2 diabetes mellitus (T2DM). Methods: Using Korean National Health Insurance Service data (2002 to 2018), the hazards of mortality from pneumonia were analyzed according to duration in LHIS (being registered to Medical Aid) during the 5 years before baseline (0, 1–4, and 5 years) among adults with T2DM who underwent health examinations between 2009 and 2012 (n=2,503,581). Hazards of outcomes were also compared in six groups categorized by insulin use and duration in LHIS. Results: During a median 7.18 years, 12,245 deaths from pneumonia occurred. Individuals who had been exposed to LHIS had higher hazards of death from pneumonia in a dose-response manner (hazard ratio [HR], 1.726; 95% confidence interval [CI], 1.568 to 1.899 and HR, 4.686; 95% CI, 3.948 to 5.562 in those exposed for 1–4 and 5 years, respectively) compared to the non-exposed reference. Insulin users exposed for 5 years to LHIS exhibited the highest outcome hazard among six groups categorized by insulin use and duration in LHIS. Conclusion Among adults with T2DM, cumulative duration in LHIS may predict increased risks of mortality from pneumonia in a graded dose-response manner. Insulin users with the longest duration in LHIS might be the group most vulnerable to death from pneumonia among adults with T2DM.

Background: We aimed to identify the risk of incident depression according to cumulative exposure to a low-household income status in individuals with type 2 diabetes mellitus (T2DM). Methods: For this retrospective longitudinal population-based cohort study, we used Korean National Health Insurance Service data from 2002 to 2018. Risk of depression was assessed according to cumulative exposure to low-household income status (defined as Medical Aid registration) during the previous 5 years among adults (aged ≥20 years) with T2DM and without baseline depression who underwent health examinations from 2009 to 2012 (n=2,027,317). Results: During an average 6.23 years of follow-up, 401,175 incident depression cases occurred. Advance in cumulative number of years registered for medical aid during the previous 5 years from baseline was associated with an increased risk of depression in a dose-dependent manner (hazard ratio [HR], 1.44 [95% confidence interval (CI), 1.38 to 1.50]; HR, 1.40 [95% CI, 1.35 to 1.46]; HR, 1.42, [95% CI, 1.37 to 1.48]; HR, 1.46, [95% CI, 1.40 to 1.53]; HR, 1.69, [95% CI, 1.63 to 1.74] in groups with 1 to 5 exposed years, respectively). Insulin users exposed for 5 years to a low-household income state had the highest risk of depression among groups categorized by insulin use and duration of low-household income status. Conclusion Cumulative duration of low-household income status, defined as medical aid registration, was associated with an increased risk of depression in a dose-response manner in individuals with T2DM.