Genome-wide search for genes affecting the age at diagnosis of type 1 diabetes

Background Type 1 diabetes (T1D) is an autoimmune disease affecting individuals in the early years of life. Although previous studies have identified genetic loci influencing T1D diagnosis age, these studies did not investigate the genome with high resolution. Objective and methods We performed a genome-wide meta-analysis for age at diagnosis with cohorts from Finland (Finnish Diabetic Nephropathy Study), the United Kingdom (UK Genetic Resource Investigating Diabetes) and Sardinia. Through SNP associations, transcriptome-wide association analysis linked T1D diagnosis age and gene expression. Results We identified two chromosomal regions associated with T1D diagnosis age: multiple independent variants in the HLA region on chromosome 6 and a locus on chromosome 17q12. We performed gene-level association tests with transcriptome prediction models from two whole blood datasets, lymphocyte cell line, spleen, pancreas and small intestine tissues. Of the non-HLA genes, lower PNMT expression in whole blood, and higher IKZF3 and ZPBP2, and lower ORMDL3 and GSDMB transcription levels in multiple tissues were associated with lower T1D diagnosis age (FDR = 0.05). These genes lie on chr17q12 which is associated with T1D, other autoimmune diseases, and childhood asthma. Additionally, higher expression of PHF20L1, a gene not previously implicated in T1D, was associated with lower diagnosis age in lymphocytes, pancreas, and spleen. Altogether, the non-HLA associations were enriched in open chromatin in various blood cells, blood vessel tissues and foetal thymus tissue. Conclusion Multiple genes on chr17q12 and PHF20L1 on chr8 were associated with T1D diagnosis age and only further studies may elucidate the role of these genes for immunity and T1D onset.Peer reviewe

Ambulatory blood pressure and arterial stiffness in individuals with type 1 diabetes

Aims/hypothesis This study aimed to assess the use of ambulatory BP monitoring (ABPM) to identify the presence of masked, nocturnal and white-coat hypertension in individuals with type 1 diabetes, patterns that could not be detected by regular office-based BP monitoring alone. We also analysed associations between BP patterns and arterial stiffness in order to identify individuals at cardiovascular risk. Methods This substudy included 140 individuals with type 1 diabetes from the Helsinki metropolitan area, who attended the Finnish Diabetic Nephropathy Study (FinnDiane) Centre in Helsinki between January 2013 and August 2017. Twenty-four hour ABPM and pulse wave analysis were performed simultaneously using a validated non-invasive brachial oscillometric device (Mobil-O-Graph). Definitions of hypertension were based on the European Society of Hypertension guidelines. Masked hypertension was defined as normal office BP (BP obtained using a standardised automated BP device) but elevated 24 h ABPM, and white-coat hypertension as elevated office BP but normal 24 h ABPM. Results A total of 38% of individuals were normotensive and 33% had sustained hypertension, while 23% had masked and 6% had white-coat hypertension. About half of the cohort had increased absolute levels of night-time BP, half of whom were untreated. In the ambulatory setting, central BP and pulse wave velocity (PWV) were higher in participants with masked hypertension than in those with normotension (p <0.001). In a multivariable linear regression model adjusted for age, sex, BMI, antihypertensive treatment and eGFR, masked hypertension was independently associated with higher 24 h PWV ((3 0.50 [95% CI 0.34, 0.66]), but not with PWV obtained during resting conditions (adjusted 13 0.28 [95% CI -0.53, 1.10]), using normotension as the reference group. Conclusions/interpretation ABPM analysis revealed that one-quarter of the participants with type 1 diabetes had masked hypertension; these individuals would not have been detected by office BP alone. Moreover, arterial stiffness was increased in individuals with masked hypertension. These findings support the use of ABPM to identify individuals at risk of cardiovascular disease.Peer reviewe

Association between habitual coffee consumption and metabolic syndrome in type 1 diabetes

Background and aims: In the general population, habitual coffee consumption is inversely associated with the metabolic syndrome, a syndrome that is rather common also in patients with type 1 diabetes. However, whether coffee intake is beneficially related to the metabolic syndrome also in type 1 diabetes, is not known. We, therefore, studied the potential association between coffee consumption and the metabolic syndrome in a large population of individuals with type 1 diabetes. Furthermore, we investigated whether coffee consumption is associated with insulin resistance (estimated glucose disposal rate, eGDR), kidney function (estimated glomerular filtration rate, eGFR), and low-grade chronic inflammation (high-sensitivity C-reactive protein, hsCRP). Methods and results: Data from 1040 participants in the Finnish Diabetic Nephropathy Study were included in these cross-sectional analyses. Metabolic syndrome was assumed if at least 3 of the following cardiovascular risk factors were present: central obesity, high blood pressure, low HDL-cholesterol concentration, high triglyceride concentration, and hyperglycaemia. Subjects were categorized based on self-reported daily coffee intake: non-consumers (= 1 cups/d = 3 cups/d = 5 cups/d). In multivariable logistic regression analysis, moderate and high coffee consumption was associated with increased odds of the metabolic syndrome. Moreover, any level of coffee consumption was associated with increased risk of the blood pressure-component. An increasing trend was observed in the eGFR with increasing coffee consumption. Conclusions: In type 1 diabetes, high coffee intake is associated with the metabolic syndrome, and especially its blood pressure-component. (C) 2018 Published by Elsevier B.V.Peer reviewe

Dose-dependent effect of smoking on risk of coronary heart disease, heart failure and stroke in individuals with type 1 diabetes

Aims/hypothesisThe aim of this study was to assess the potential dose-dependent effects of smoking on the risk of CHD, heart failure and stroke in individuals with type 1 diabetes.MethodsThe study included 4506 individuals with type 1 diabetes who were participating in the Finnish Diabetic Nephropathy (FinnDiane) study. Intensity of smoking was estimated by packs per day and cumulative smoking by pack-years. Cox regression analyses were used to estimate the risk of incident CHD, heart failure or stroke during follow-up.ResultsOne pack per day significantly increased the risk of incident CHD in current smokers compared with never smokers (HR 1.45 [95% CI 1.15, 1.84]), after adjustment for age, sex, HbA(1c), hypertension, duration of diabetes and BMI. The risk of CHD in former smokers was similar to the risk in never smokers. The risk of incident heart failure was 1.43 (95% CI 1.03, 1.97) in current smokers per one pack per day and 1.37 (95% CI 1.05, 1.77) in former smokers, while the risk of incident stroke was 1.70 (95% CI 1.26, 2.29) and 1.49 (95% CI 1.14, 1.93), respectively. After further adjustments for lipids, however, the difference in the risk of heart failure in current and former smokers was no longer significant. Cumulative smoking data were similar to smoking intensity data.Conclusions/interpretationThere is a dose-dependent association between smoking and cardiovascular disease in individuals with type 1 diabetes. In men in particular, the risk of incident stroke remains high even after smoking cessation and is increased in current and former smokers independently of other risk factors.Peer reviewe

Association between diet and measures of arterial stiffness in type 1 diabetes - Focus on dietary patterns and macronutrient substitutions

Background and aims: Increased arterial stiffness contributes to diabetic vascular complications. We identified dietary factors related to arterial stiffness in individuals with type 1 diabetes, a population with high risk of cardiovascular disease. Methods and results: Altogether, 612 participants (40% men, mean +/- standard deviation age 45 +/- 13 years) completed a validated diet questionnaire and underwent measurements of arterial stiffness. Of these, 470 additionally completed a food record. Exploratory factor analysis was applied to identify dietary patterns from the diet questionnaires, and nutrient intakes were calculated from food record entries. Arterial stiffness was measured by applanation tonometry. Of the seven dietary factors formed, the factor scores of "Full-fat cheese and eggs" and "Sweet" patterns were negatively associated with measures of arterial stiffness. In the multivariable macronutrient substitution models, favouring carbohydrates over fats was associated with higher aortic mean arterial pressure and aortic pulse wave velocity. When carbohydrates were consumed in place of proteins, higher aortic pulse pressure, aortic mean arterial pressure, and augmentation index were recorded. Replacing energy from alcohol with proteins, was associated with lower aortic pulse pressure, aortic mean arterial pressure, and augmentation index. Relative distributions of dietary fatty acids were neutral with respect to the measures of arterial stiffness. Conclusion: The macronutrient distribution of the diet is likely to affect the resilience of the arteries. Our observations suggest that reducing energy intake from carbohydrates and alcohol may be beneficial. These observations, especially those dealing with dietary patterns, need to be confirmed in a longitudinal study. (C) 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.Peer reviewe

Symptoms of depression are associated with reduced leisure-time physical activity in adult individuals with type 1 diabetes

Aims Here, we investigated the association between depressive symptoms and leisure-time physical activity (LTPA) in type 1 diabetes. Methods Data from adult individuals with type 1 diabetes without evidence of diabetic kidney disease or macrovascular complications, participating in the Finnish Diabetic Nephropathy Study, were included. Based on a questionnaire, weekly LTPA as metabolic equivalent of task hour was calculated. Activity levels (inactive, moderately active, active), weekly frequencies ( 2), intensities (low, moderate, high), and single session durations ( 60 min) were assessed. Depressive symptomatology was evaluated using the Beck Depression Inventory (BDI). We calculated a continuous BDI score and divided participants into those with (BDI score >= 16) and without (BDI score < 16) symptoms of depression. For sensitivity analyses, we additionally defined symptoms of depression with antidepressant agent purchases within a year from the study visit. Results Of the 1339 participants (41.7% men, median age 41 years), 150 (11.2%) reported symptoms of depression. After adjustments, both higher BDI scores and depressive symptomatology were associated with more inactive lifestyle, and lower frequency and intensity of the LTPA. The BDI score was additionally associated with shorter single session duration. For antidepressant purchases, lower odds were observed in those with higher intensity and longer single session duration of LTPA. Conclusions Depressive mood is harmfully related to LTPA in type 1 diabetes. In order to improve the long-term health of individuals with type 1 diabetes, efforts to increase both mental well-being and physical activity should be taken.Peer reviewe

Resistant Hypertension and Risk of Adverse Events in Individuals With Type 1 Diabetes : A Nationwide Prospective Study

OBJECTIVE To estimate the risk of diabetic nephropathy (DN) progression, incident coronary heart disease (CHD) and stroke, and all-cause mortality associated with resistant hypertension (RH) in individuals with type 1 diabetes stratified by stages of DN, renal function, and sex. RESEARCH DESIGN AND METHODS This prospective study included a nationally representative cohort of individuals with type 1 diabetes from the Finnish Diabetic Nephropathy Study who had purchases of antihypertensive drugs at (+/- 6 months) baseline visit (1995-2008). Individuals (N= 1,103) were divided into three groups:1) RH,2) uncontrolled blood pressure (BP) but no RH, and3) controlled BP. DN progression, cardiovascular events, and deaths were identified from the individuals' health care records and national registries until 31 December 2015. RESULTS At baseline, 18.7% of the participants had RH, while 23.4% had controlled BP. After full adjustments for clinical confounders, RH was associated with increased risk of DN progression (hazard ratio 1.95 [95% CI 1.37, 2.79],P= 0.0002), while no differences were observed in those with no RH (1.05 [0.76, 1.44],P= 0.8) compared with those who had controlled BP. The risk of incident CHD, incident stroke, and all-cause mortality was higher in individuals with RH compared with those who had controlled BP but not beyond albuminuria and reduced kidney function. Notably, in those with normo- and microalbuminuria, the risk of stroke remained higher in the RH compared with the controlled BP group (3.49 [81.20, 10.15],P= 0.02). CONCLUSIONS Our findings highlight the importance of identifying and providing diagnostic and therapeutic counseling to these very-high-risk individuals with RH.Peer reviewe

Relationship between ABO blood groups and cardiovascular disease in type 1 diabetes according to diabetic nephropathy status

Background ABO blood groups have previously been associated with cardiovascular disease (CVD) in the general population. This study aimed to investigate the potential relationship between ABO blood groups and CVD in individuals with type 1 diabetes according to diabetic nephropathy (DN) status. Methods Adults with type 1 diabetes (4531 individuals) from the FinnDiane Study were evaluated. DN was determined by two out of three measurements of urinary albumin excretion rate. Albuminuria was defined as an excretion rate above 20 mu g/min. CVD events were identified by linking the data with the Finnish Care Register for Health Care and the Finnish Cause of Death Register. Follow-up ranged from the baseline visit until a CVD event, death or the end of 2017. The impact of ABO blood groups on CVD risk was estimated by multivariable Cox-regression analyses adjusted for traditional risk factors. Results At baseline, the median age was 38.5 (IQR 29.2-47.9) years, 47.5% were female and median duration of diabetes was 20.9 (11.4-30.7) years. There were 893 incident ischemic heart disease (IHD) events, 301 ischemic strokes (IS), and 415 peripheral artery disease (PAD) events during a median follow up of 16.5 (IQR 12.8-18.6) years. The A blood group showed the highest risk of IHD versus the O blood group, when microalbuminuria was present. Comparing the population with microalbuminuria with those with normoalbuminuria, only the A blood group elevated the risk of IHD. This increased risk was neither explained by the FUT2 secretor phenotype nor by the A-genotype distribution. The risk of IS or PAD was no different among the ABO blood groups regardless of diabetic nephropathy stage. Conclusion The A blood group is a risk factor for IHD in individuals with type 1 diabetes and microalbuminuria.Peer reviewe

Association between adherence to dietary recommendations and high-sensitivity C-reactive protein level in type 1 diabetes

Aims: Inflammation plays an important role in the pathogenesis of cardiovascular diseases. Diet, as a modifiable risk factor, may in turn impact systemic inflammation. We therefore assessed whether adherence to the dietary recommendations is associated with high-sensitivity C-reactive protein (hs-CRP) concentrations in type 1 diabetes. Methods: Cross-sectional data from 677 FinnDiane study participants (48% men, mean +/- standard deviation age 46 +/- 13 years) were included. Dietary intake was assessed with a self-administered questionnaire. A diet score, with higher values denoting better adherence to the recommendations, was calculated. Serum hs-CRP concentration was measured, and individuals with hs-CRP 3.0 but <10.0 mg/l were compared. Results: Men and women with high hs-CRP had higher BMI, waist circumference, and triglyceride concentration, but lower HDL-cholesterol concentration. Adjusted for BMI, mean diet score was higher in the low hs-CRP group, both in men (10.8 +/- 3.6 vs. 9.9 +/- 3.8, p = 0.023) and women (12.7 +/- 3.4 vs. 11.6 +/- 3.5, p = 0.021). After further adjustments with potential confounding factors, the difference remained significant only in men. Conclusions: A diet that more closely adheres to the dietary recommendations is associated with lower hs-CRP in men. A prudent diet may help reduce systemic inflammation in type 1 diabetes. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

Data-driven metabolic subtypes predict future adverse events in individuals with type 1 diabetes

Aims/hypothesis Previously, we proposed that data-driven metabolic subtypes predict mortality in type 1 diabetes. Here, we analysed new clinical endpoints and revisited the subtypes after 7 years of additional follow-up. Methods Finnish individuals with type 1 diabetes (2059 men and 1924 women, insulin treatment before 35 years of age) were recruited by the national multicentre FinnDiane Study Group. The participants were assigned one of six metabolic subtypes according to a previously published self-organising map from 2008. Subtype-specific all-cause and cardiovascular mortality rates in the FinnDiane cohort were compared with registry data from the entire Finnish population. The rates of incident diabetic kidney disease and cardiovascular endpoints were estimated based on hospital records. Results The advanced kidney disease subtype was associated with the highest incidence of kidney disease progression (67.5% per decade, p <0.001), ischaemic heart disease (26.4% per decade, p <0.001) and all-cause mortality (41.5% per decade, p <0.001). Across all subtypes, mortality rates were lower in women compared with men, but standardised mortality ratios (SMRs) were higher in women. SMRs were indistinguishable between the original study period (19942007) and the new period (2008-2014). The metabolic syndrome subtype predicted cardiovascular deaths (SMR 11.0 for men, SMR 23.4 for women, p <0.001), and women with the high HDL-cholesterol subtype were also at high cardiovascular risk (SMR 16.3, p <0.001). Men with the low-cholesterol or good glycaemic control subtype showed no excess mortality. Conclusions/interpretation Data-driven multivariable metabolic subtypes predicted the divergence of complication burden across multiple clinical endpoints simultaneously. In particular, men with the metabolic syndrome and women with high HDL-cholesterol should be recognised as important subgroups in interventional studies and public health guidelines on type 1 diabetes.Peer reviewe