Risk of atrial fibrillation in persons with type 2 diabetes and the excess risk in relation to glycaemic control and renal function: a Swedish cohort study.

BACKGROUND: To examine the incidence of atrial fibrillation in individuals with type 2 diabetes compared with age- and sex-matched controls from the general population and its variation in relation to glycaemic control and renal function. METHODS: A total of 421,855 patients with type 2 diabetes from the Swedish National Diabetes Registry and 2,131,223 controls from the Swedish Population Registry, matched for age, sex and county, were included and followed from January 1, 2001 to December 31, 2013. RESULTS: Overall, 8.9% of individuals with type 2 diabetes and 7.0% of controls were diagnosed with atrial fibrillation during follow-up, unadjusted incidence risk ratio (IRR) 1.35 (95% 1.33-1.36). Women < 55 years old with type 2 diabetes had an IRR of 2.36 (95% CI 2.10-2.66), in relation to controls, whereas the corresponding value for men < 55 years old with type 2 diabetes was IRR 1.78 (95% CI 1.67-1.90). In the fully adjusted Cox regression, the risk of type 2 diabetes on incident atrial fibrillation was 28% greater vs controls, hazard ratio (HR) 1.28 (95% CI 1.26-1.30), p < 0.0001. The excess risk of atrial fibrillation in individuals with type 2 diabetes increased with worsening glycaemic control and renal complications. For individuals with HbA1c ≤ 6.9% (≤ 52 mmol/mol) and normoalbuminuria the excess risk vs controls was still increased, adjusted HR 1.16 (95% CI 1.14-1.19); p < 0.0001. CONCLUSIONS: Individuals with type 2 diabetes had an overall 35% higher risk of atrial fibrillation compared to age- and sex-matched controls from the general population. The excess risk for atrial fibrillation increased with renal complications or with poor glycaemic control. Individuals with type 2 diabetes with good glycaemic control and normoalbuminuria had slightly increased risk.

Risk factors for nephropathy in persons with type 1 diabetes: a population-based study.

AIMS: Albuminuria is strongly associated with risk of renal dysfunction, cardiovascular disease and mortality. However, clinical guidelines diverge, and evidence is sparse on what risk factor levels regarding blood pressure, blood lipids and BMI are needed to prevent albuminuria in adolescents and young adults with type 1 diabetes. METHODS: A total of 9347 children and adults with type 1 diabetes [mean age 15.3 years and mean diabetes duration 1.4 years at start of follow-up] from The Swedish National Diabetes Registry were followed from first registration until end of 2017. Levels for risk factors for a risk increase in nephropathy were evaluated, and the gradient of risk per 1 SD (standard deviation) was estimated to compare the impact of each risk factor. RESULTS: During the follow-up period, 8610 (92.1%) remained normoalbuminuric, 737 (7.9%) individuals developed micro- or macroalbuminuria at any time period of whom 132 (17.9% of 737) individuals developed macroalbuminuria. Blood pressure ≥ 140/80 mmHg was associated with increased risk of albuminuria (p ≤ 0.0001), as were triglycerides ≥ 1.0 mmol/L (p = 0.039), total cholesterol ≥ 5.0 mmol/L (p = 0.0003), HDL < 1.0 mmol/L (p = 0.013), LDL 3.5- < 4.0 mmol/L (p = 0.020), and BMI ≥ 30 kg/m2 (p = 0.033). HbA1c was the strongest risk factor for any albuminuria estimated by the measure gradient of risk per 1 SD, followed by diastolic blood pressure, triglycerides, systolic blood pressure, cholesterol and LDL. In patients with HbA1c > 65 mmol/mol (> 8.1%), blood pressure > 140/70 mmHg was associated with increased risk of albuminuria. CONCLUSIONS: Preventing renal complications in adolescents and young adults with type 1 diabetes need avoidance at relatively high levels of blood pressure, blood lipids and BMI, whereas very tight control is not associated with further risk reduction. For patients with long-term poor glycaemic control, stricter blood pressure control is advocated.

The Association Between HbA1c and Time in Hypoglycemia During CGM and Self-Monitoring of Blood Glucose in People With Type 1 Diabetes and Multiple Daily Insulin Injections: A Randomized Clinical Trial (GOLD-4).

OBJECTIVE: According to recent guidelines, individuals with type 1 diabetes should spend <4.0% of time per day with glucose levels <3.9 mmol/L (<70 mg/dL) and <1.0% per day with glucose levels <3.0 mmol/L (<54 mg/dL). RESEARCH DESIGN AND METHODS: In the GOLD randomized crossover trial, 161 individuals with type 1 diabetes treated with multiple daily insulin injections (MDI) were randomized to continuous glucose monitoring (CGM) or conventional therapy with self-monitoring of blood glucose (SMBG) and evaluated over 16 months. We estimated the association between time spent in hypoglycemia and various mean glucose and HbA1c levels. RESULTS: Time spent in hypoglycemia (<3.9 mmol/L and <3.0 mmol/L) increased significantly with lower mean HbA1c and mean glucose levels during both CGM and conventional therapy. During CGM, 24 (57.1%) individuals with HbA1c <7.5% (<58 mmol/mol) had <1.0% time spent in hypoglycemia <3.0 mmol/L and 23 (54.8%) had <4.0% time spent in hypoglycemia <3.9 mmol/L. During CGM, mean time spent in hypoglycemia for individuals with mean HbA1c 7.0% (52 mmol/mol) was estimated to be 5.4% for <3.9 mmol/L and 1.5% for <3.0 mmol/L. The corresponding values during SMBG were 9.2% and 3.5%, respectively. Individuals with mean glucose levels of 8 mmol/L spent 4.9% units more time with glucose levels <3.9 mmol/L and 2.8% units more time <3.0 mmol/L during SMBG compared with CGM. CONCLUSIONS: Reaching current targets for time in hypoglycemia while at the same time reaching HbA1c targets is challenging for patients with type 1 diabetes treated with MDI both with CGM and SMBG monitoring. However, CGM is associated with considerably less time in hypoglycemia than SMBG at a broad range of HbA1c levels and is crucial for patients with MDI treatment if they are to have a chance to approach hypoglycemia targets.