Short Report: Treatment Intensive multifactorial treatment modifies the effect of family history of diabetes on glycaemic control in people with Type 2 diabetes: a post hoc analysis of the ADDITION- Denmark randomized controlled trial G. M. Eliraqi 1,2 , D. Vistisen 1 , T. Lauritzen 3 , A. Sandbæk 3 , M. E. Jørgensen 1 and K. Færch 1 1 Steno Diabetes Center, Gentofte, Denmark, 2 Faculty of Medicine, Lund University, Malm€ o, Sweden and 3 Institute of Public Health, Aarhus University, Aarhus, Denmark Accepted 24 March 2015 Abstract Aim To investigate whether intensive multifactorial treatment can reverse the predisposed adverse phenotype of people with Type 2 diabetes who have a family history of diabetes. Methods Data from the randomized controlled trial ADDITION-Denmark were used. A total of 1441 newly diagnosed patients with diabetes (598 with family history of diabetes) were randomized to intensive treatment or routine care. Family history of diabetes was defined as having one parent and/or sibling with diabetes. Linear mixed-effects models were used to assess the changes in risk factors (BMI, waist circumference, blood pressure, lipids and HbA 1c ) after 5 years of follow-up in participants with and without a family history of diabetes. An interaction term between family history of diabetes and treatment group was included in the models to test for a modifying effect of the intervention. All analyses were adjusted for age, sex, baseline value of the risk factor and general practice (random effect). Results At baseline, participants with a family history of diabetes were younger and had a 1.1 mmol/mol (0.1%) higher HbA 1c concentration at the time of diagnosis than those without a family history of diabetes. Family history of diabetes modified the effect of the intervention on changes in HbA 1c levels. In the group receiving routine care, participants with a family history of diabetes experienced an improvement in HbA 1c concentration that was 3.3 mmol/mol (0.3%) lower than the improvement found in those without a family history of diabetes after 5 years of follow-up. In the intensive treatment group, however, there was no difference in HbA 1c concentrations between participants with and without a family history of diabetes after 5 years of treatment. Conclusions Intensive treatment of diabetes may partly remove the adverse effects of family history of diabetes on glycaemic control. The effect of this improvement on long-term diabetic complications warrants further investigation. Diabet. Med. 32, 1085–1089 (2015) Introduction Type 2 diabetes is a heterogeneous metabolic disorder. The course of the disease is determined by a number of genetic, behavioural and environmental factors. Family history of diabetes reflects a combination of these factors and may be an effective clinical tool to guide not only the screening and prognosis but also the treatment of the disease [1]. People with a family history of diabetes have a 3–4-fold higher risk of developing diabetes than those without a family history of diabetes [2,3]. Family history of diabetes is also commonly used in diabetes risk assessment tools, including the Danish Inter99 questionnaire [4]. Recent studies show, however, that family history of diabetes is not only a predictor of the incidence of the disease, but also of the severity. In the Finnish Botnia study, it was found that people with diabetes who had a family history of diabetes were significantly younger at diagnosis, had lower HDL cholesterol levels, higher BMI and higher fasting C-peptide concentrations [4]. In another study from Japan, family history of diabetes was associated with a higher BMI, higher levels of triglycerides and a higher incidence of cardiovascu- lar disease and metabolic alterations among people with diabetes [6]. In an African-American population, family Correspondence to: Kristine Færch. E-mail: krif@steno.dk. ª 2015 The Authors. Diabetic Medicine ª 2015 Diabetes UK 1085 DIABETICMedicine DOI: 10.1111/dme.12764