Impact of Age of Onset, Puberty, and Glycemic Control Followed From Diagnosis on Incidence of Retinopathy in Type 1 Diabetes: The VISS Study.

To evaluate sex, age at diabetes onset, puberty, and HbA1c, with subjects followed from diabetes diagnosis and during different time periods, as risk factors for developing diabetic simplex and proliferative retinopathy. In a population-based observational study, HbA1c for 451 patients diagnosed with diabetes before 35 years of age during 1983-1987 in southeast Sweden was followed for up to 18-24 years from diagnosis. Long-term mean weighted HbA1c (wHbA1c) was calculated. Retinopathy was evaluated by fundus photography and analyzed in relation to wHbA1c levels. Lower wHbA1c, diabetes onset ≤5 years of age, and diabetes onset before puberty, but not sex, were associated with longer time to appearance of simplex retinopathy. Proliferative retinopathy was associated only with wHbA1c. The time to first appearance of any retinopathy decreased with increasing wHbA1c. Lower wHbA1c after ≤5 years' diabetes duration was associated with later onset of simplex retinopathy but not proliferative retinopathy. With time, most patients developed simplex retinopathy, except for those of the category wHbA1c ≤50 mmol/mol (6.7%), for which 20 of 36 patients were without any retinopathy at the end of the follow-up in contrast to none of 49 with wHbA1c >80 mmol/mol (9.5%). Onset at ≤5 years of age and lower wHbA1c the first 5 years after diagnosis are associated with longer duration before development of simplex retinopathy. There is a strong positive association between long-term mean HbA1c measured from diagnosis and up to 20 years and appearance of both simplex and proliferative retinopathy.

Nordwall M ，Fredriksson M ，Ludvigsson J ，Arnqvist HJ ... -  《-》

Impact of HbA1c Followed 32 Years From Diagnosis of Type 1 Diabetes on Development of Severe Retinopathy and Nephropathy: The VISS Study.

To evaluate HbA1c followed from diagnosis, as a predictor of severe microvascular complications (i.e., proliferative diabetic retinopathy [PDR] and nephropathy [macroalbuminuria]). In a population-based observational study, 447 patients diagnosed with type 1 diabetes before 35 years of age from 1983 to 1987 in southeast Sweden were followed from diagnosis until 2019. Long-term weighted mean HbA1c (wHbA1c) was calculated by integrating the area under all HbA1c values. Complications were analyzed in relation to wHbA1c categorized into five levels. After 32 years, 9% had no retinopathy, 64% non-PDR, and 27% PDR, and 83% had no microalbuminuria, 9% microalbuminuria, and 8% macroalbuminuria. Patients with near-normal wHbA1c did not develop PDR or macroalbuminuria. The lowest wHbA1c values associated with development of PDR and nephropathy (macroalbuminuria) were 7.3% (56 mmol/mol) and 8.1% (65 mmol/mol), respectively. The prevalence of PDR and macroalbuminuria increased with increasing wHbA1c, being 74% and 44% in the highest category, wHbA1c >9.5% (>80 mmol/mol). In comparison with the follow-up done after 20-24 years' duration, the prevalence of PDR had increased from 14 to 27% and macroalbuminuria from 4 to 8%, and both appeared at lower wHbA1c values. wHbA1c followed from diagnosis is a very strong biomarker for PDR and nephropathy, the prevalence of both still increasing 32 years after diagnosis. To avoid PDR and macroalbuminuria in patients with type 1 diabetes, an HbA1c <7.0% (53 mmol/mol) and as normal as possible should be recommended when achievable without severe hypoglycemia and with good quality of life.

Arnqvist HJ ，Westerlund MC ，Fredrikson M ，Ludvigsson J ，Nordwall M ... -  《-》

Impact of HbA1c, followed from onset of type 1 diabetes, on the development of severe retinopathy and nephropathy: the VISS Study (Vascular Diabetic Complications in Southeast Sweden).

HbA1c is strongly related to the development of diabetes complications, but it is still controversial which HbA1c level to strive for in the treatment of type 1 diabetes. The aim of the current study was to evaluate HbA1c, followed from diagnosis, as a predictor of severe microvascular complications and to formulate HbA1c target levels for treatment. A longitudinal observation study followed an unselected population of 451 patients diagnosed with type 1 diabetes during 1983-1987 before the age of 35 years in a region of Southeast Sweden. Retinopathy was evaluated by fundus photography and nephropathy data collected from medical records. HbA1c was measured starting from diagnosis and during the whole follow-up period of 20-24 years. Long-term weighted mean HbA1c was then calculated. Complications were analyzed in relation to HbA1c levels. The incidence of proliferative retinopathy and persistent macroalbuminuria increased sharply and occurred earlier with increasing long-term mean HbA1c. None of the 451 patients developed proliferative retinopathy or persistent macroalbuminuria below long-term weighted mean HbA1c 7.6% (60 mmol/mol); 51% of the patients with long-term mean HbA1c above 9.5% (80 mmol/mol) developed proliferative retinopathy and 23% persistent macroalbuminuria. Long-term weighted mean HbA1c, measured from diagnosis, is closely associated with the development of severe complications in type 1 diabetes. Keeping HbA1c below 7.6% (60 mmol/mol) as a treatment target seems to prevent proliferative retinopathy and persistent macroalbuminuria for up to 20 years.

Nordwall M ，Abrahamsson M ，Dhir M ，Fredrikson M ，Ludvigsson J ，Arnqvist HJ ... -  《-》

Early increase in HbA1c trajectory predicts development of severe microangiopathy in patients with type 1 diabetes: the VISS study.

To study the HbA1c trajectory from the time of diagnosis to examine if patients at the greatest risk for severe microangiopathy can be identified early allowing clinicians to intervene as soon as possible to avoid complications. In a population-based observational study, 447 patients diagnosed with type 1 diabetes before 35 years of age, 1983-1987, were followed from diagnosis until 2019. Mean HbA1c was calculated each year for each patient. Severe diabetic microangiopathy was defined as proliferative diabetic retinopathy (PDR) or macroalbuminuria (nephropathy). After 32 years, 27% had developed PDR and 8% macroalbuminuria. Patients with weighted HbA1c (wHbA1c); <57 mmol/mol; <7.4% did not develop PDR or macroalbuminuria. The HbA1c trajectories for patients developing PDR and macroalbuminuria follow separate courses early on and stay separated for 32 years during the follow-up. Patients without severe complications show an initial dip, after which HbA1c slowly increases. HbA1c in patients with severe complications directly rises to a high level within a few years. Mean HbA1c calculated for the period 5-8 years after diabetes onset strongly predicts the development of severe complications. Females with childhood-onset diabetes exhibit a high peak in HbA1c during adolescence associated with higher wHbA1c and higher prevalence of PDR. The HbA1c trajectory from diabetes onset shows that mean HbA1c for the period 5-8 years after diagnosis strongly predicts severe microangiopathy. Females with childhood-onset diabetes exhibit a high peak in HbA1c during adolescence associated with higher wHbA1c and a higher prevalence of PDR.

Arnqvist HJ ，Ludvigsson J ，Nordwall M 《BMJ Open Diabetes Research &amp; Care》

HbA(1c) level as a risk factor for retinopathy and nephropathy in children and adults with type 1 diabetes: Swedish population based cohort study.

To evaluate if the lowest target level for glycated haemoglobin (HbA1c) of <6.5% is associated with lower risk for retinopathy and nephropathy than less tight control in children and adults with type 1 diabetes. Population based cohort study. Swedish National Diabetes Registry, 1 January 1998 to 31 December 2017. 10 398 children and adults with type 1 diabetes followed from diagnosis, or close thereafter, until end of 2017. Relative risk (odds ratios) for retinopathy and nephropathy for different mean levels of HbA1c. Mean age of participants was 14.7 years (43.4% female), mean duration of diabetes was 1.3 years, and mean HbA1c level was 8.0% (63.4 mmol/mol). After adjustment for age, sex, duration of diabetes, blood pressure, blood lipid levels, body mass index, and smoking, the odds ratio for mean HbA1c <6.5% (<48 mmol/mol) compared with 6.5-6.9% (48-52 mmol/mol) for any retinopathy (simplex or worse) was 0.77 (95% confidence interval 0.56 to 1.05, P=0.10), for preproliferative diabetic retinopathy or worse was 3.29 (0.99 to 10.96, P=0.05), for proliferative diabetic retinopathy was 2.48 (0.71 to 8.62, P=0.15), for microalbuminuria or worse was 0.98 (0.60 to 1.61, P=0.95), and for macroalbuminuria was 2.47 (0.69 to 8.87, P=0.17). Compared with HbA1c levels 6.5-6.9%, HbA1c levels 7.0-7.4% (53-57 mmol/mol) were associated with an increased risk of any retinopathy (1.31, 1.05 to 1.64, P=0.02) and microalbuminuria (1.55, 1.03 to 2.32, P=0.03). The risk for proliferative retinopathy (5.98, 2.10 to 17.06, P<0.001) and macroalbuminuria (3.43, 1.14 to 10.26, P=0.03) increased at HbA1c levels >8.6% (>70 mmol/mol). The risk for severe hypoglycaemia was increased at mean HbA1c <6.5% compared with 6.5-6.9% (relative risk 1.34, 95% confidence interval 1.09 to 1.64, P=0.005). Risk of retinopathy and nephropathy did not differ at HbA1c levels <6.5% but increased for severe hypoglycaemia compared with HbA1c levels 6.5-6.9%. The risk for severe complications mainly occurred at HbA1c levels >8.6%, but for milder complications was increased at HbA1c levels >7.0%.

Lind M ，Pivodic A ，Svensson AM ，Ólafsdóttir AF ，Wedel H ，Ludvigsson J ... -  《BMJ-British Medical Journal》