Clustering of risk factors in parents of patients with type 1 diabetes and nephropathy

The impact of parental risk factors on the risk of stroke in type 1 diabetes

BACKGROUND

Individuals with type 1 diabetes have a markedly increased risk of stroke. In the general population, genetic predisposition has been linked to increased risk of stroke, but this has not been assessed in type 1 diabetes. Our aim was, therefore, to study how parental risk factors affect the risk of stroke in individuals with type 1 diabetes.

METHODS

This study represents an observational follow-up of 4011 individuals from the Finnish Diabetic Nephropathy Study, mean age at baseline 37.6 ± 11.9 years. All strokes during follow-up were verified from medical records or death certificates. The strokes were classified as either ischemic or hemorrhagic. All individuals filled out questionnaires concerning their parents' medical history of hypertension, diabetes, stroke, and/or myocardial infarction.

RESULTS

During a median follow-up of 12.4 (10.9-14.2) years, 188 individuals (4.6%) were diagnosed with their first ever stroke; 134 were ischemic and 54 hemorrhagic. In Cox regression analysis, a history of maternal stroke increased the risk of hemorrhagic stroke, hazard ratio 2.86 (95% confidence interval 1.27-6.44, p = 0.011) after adjustment for sex, age, BMI, retinal photocoagulation, and diabetic kidney disease. There was, however, no association between maternal stroke and ischemic stroke. No other associations between parental risk factors and ischemic or hemorrhagic stroke were observed.

CONCLUSION

A history of maternal stroke increases the risk of hemorrhagic stroke in individuals with type 1 diabetes. Other parental risk factors seem to have limited impact on the risk of stroke.

Clustering of cardio-metabolic risk factors in parents of adolescents with type 1 diabetes and microalbuminuria

OBJECTIVE

To evaluate the association between a clustering of cardio-metabolic risk factors in parents and the development of microalbuminuria (MA) in their offspring with childhood-onset type 1 diabetes (T1D).

METHODS

The study population comprised 53 parents (mean age [±SD]: 56.7±6.2 years) of 35 T1D young people with MA (MA+) and 86 parents (age: 56.1±6.3 years) of 50 matched offspring with normoalbuminuria (MA-), who underwent clinical, biochemical and cardiovascular imaging assessments. The primary study endpoint was the difference between parents from the MA+ and MA- groups in a cardio-metabolic risk score, calculated as the average value of the standardized measures (z-scores) for waist circumference, blood pressure, fasting glucose, insulin, HDL-cholesterol and triglycerides levels. Cardiovascular parameters, including carotid intima-media thickness (cIMT), flow-mediated dilatation (FMD) and pulse wave velocity (PWV), were also assessed. A DXA scan was performed to assess body composition.

RESULTS

The cardio-metabolic risk score was significantly higher in parents of MA+ compared to parents of MA- offspring (mean [95% CI]: 1.066[0.076; 2.056] vs -0.268[-0.997; 0.460], P = .03). Parents of MA+ offspring had slightly higher values of waist circumference, lipids, insulin and blood pressure, although only diastolic blood pressure was statistically different between the 2 groups (P = .0085). FMD, cIMT, PWV (all P > .3), and DXA parameters (all P > .2) were not significantly different between the 2 groups.

CONCLUSIONS

Parents of young offspring with childhood-onset T1D and MA showed an abnormal metabolic profile, reflected by a calculated risk score. The finding supports the role of a familial predisposition to risk of developing diabetic nephropathy.

Serum Insulin Bioassay Reflects Insulin Sensitivity and Requirements in Type 1 Diabetes

CONTEXT

Insulin resistance could increase insulin requirements in type 1 diabetes (T1D). Current insulin immunoassays do not detect insulin analogs. Kinase insulin receptor (IR) activation (KIRA) bioassays specific for human IR isoforms A (IR-A) and B (IR-B) permit assessment of all circulating insulin bioactivity. We studied whether IR-A and IR-B KIRA assays are related to direct measures of insulin sensitivity or insulin doses in T1D.

DESIGN

We evaluated 31 adult patients with T1D (age 45.7 ± 1.6 years, body mass index 28.8 ± 0.7 kg/m2). Serum IR-A and IR-B bioactivities were measured by KIRA bioassays. Insulin sensitivity of glucose production (Ra) was measured by the euglycemic hyperinsulinemic clamp technique in which a low insulin dose (0.4 mU/kg/min for 240 minutes) was combined with D-[3-3H] glucose infusion to measure rates of Ra and utilization and insulin action on antilipolysis from suppression of serum free fatty acids.

RESULTS

Baseline circulating IR-A bioactivity was 53 ± 7 pmol/L, and IR-B bioactivity was 81 ± 11 pmol/L. Compared with baseline, insulin infusion significantly increased IR-A (P < 0.001) and IR-B (P < 0.001) bioactivities. Fasting IR-A and IR-B bioactivities were positively related to endogenous Ra (r = 0.44, P = 0.01 and r = 0.38, P < 0.05). Fasting IR-A (r = 0.43, P = 0.02) and IR-B (r = 0.47, P = 0.01) bioactivities were significantly correlated with insulin requirements and glycosylated hemoglobin (IR-A: r = 0.52, P = 0.002; IR-B: r = 0.48, P = 0.006).

CONCLUSIONS

Circulating IR-A and IR-B bioactivities are associated with insulin resistance, high insulin requirements, and poor glycemic control in T1D. Measurement of IR bioactivity by KIRA assays provides a tool to assess the amount of biologically active insulin in groups of T1D patients treated with insulin analogs.

Differentiation of Diabetes by Pathophysiology, Natural History, and Prognosis

The American Diabetes Association, JDRF, the European Association for the Study of Diabetes, and the American Association of Clinical Endocrinologists convened a research symposium, "The Differentiation of Diabetes by Pathophysiology, Natural History and Prognosis" on 10-12 October 2015. International experts in genetics, immunology, metabolism, endocrinology, and systems biology discussed genetic and environmental determinants of type 1 and type 2 diabetes risk and progression, as well as complications. The participants debated how to determine appropriate therapeutic approaches based on disease pathophysiology and stage and defined remaining research gaps hindering a personalized medical approach for diabetes to drive the field to address these gaps. The authors recommend a structure for data stratification to define the phenotypes and genotypes of subtypes of diabetes that will facilitate individualized treatment.

The Genetic Landscape of Renal Complications in Type 1 Diabetes

Diabetes is the leading cause of ESRD. Despite evidence for a substantial heritability of diabetic kidney disease, efforts to identify genetic susceptibility variants have had limited success. We extended previous efforts in three dimensions, examining a more comprehensive set of genetic variants in larger numbers of subjects with type 1 diabetes characterized for a wider range of cross-sectional diabetic kidney disease phenotypes. In 2843 subjects, we estimated that the heritability of diabetic kidney disease was 35% (P=6.4×10^-3). Genome-wide association analysis and replication in 12,540 individuals identified no single variants reaching stringent levels of significance and, despite excellent power, provided little independent confirmation of previously published associated variants. Whole-exome sequencing in 997 subjects failed to identify any large-effect coding alleles of lower frequency influencing the risk of diabetic kidney disease. However, sets of alleles increasing body mass index (P=2.2×10^-5) and the risk of type 2 diabetes (P=6.1×10^-4) associated with the risk of diabetic kidney disease. We also found genome-wide genetic correlation between diabetic kidney disease and failure at smoking cessation (P=1.1×10^-4). Pathway analysis implicated ascorbate and aldarate metabolism (P=9.0×10^-6), and pentose and glucuronate interconversions (P=3.0×10^-6) in pathogenesis of diabetic kidney disease. These data provide further evidence for the role of genetic factors influencing diabetic kidney disease in those with type 1 diabetes and highlight some key pathways that may be responsible. Altogether these results reveal important biology behind the major cause of kidney disease.

Progression of cardio-metabolic risk factors in subjects born small and large for gestational age

Background

Subjects born small (SGA) and large (LGA) for gestational age have an increased risk of cardio-metabolic alterations already during prepuberty. Nevertheless, the progression of their cardio-metabolic profile from childhood to adolescence has not been fully explored. Our aim was to assess potential changes in the cardio-metabolic profile from childhood to adolescence in subjects born SGA and LGA compared to those born appropriate (AGA) for gestational age.

Methods

This longitudinal study included 35 AGA, 24 SGA and 31 LGA subjects evaluated during childhood (mean age (±SD) 8.4±1.4 yr) and then re-assessed during adolescence (mean age 13.3±1.8 yr). BMI, blood pressure, insulin resistance (fasting insulin, HOMA-IR) and lipids were assessed. A cardio-metabolic risk z-score was applied and this consisted in calculating the sum of sex-specific z-scores for BMI, blood pressure, HOMA-IR, triglycerides and triglycerides:high-density lipoprotein cholesterol ratio.

Results

Fasting insulin and HOMA-IR were higher in SGA and LGA than AGA subjects both during childhood (all P<0.01) and adolescence (all P<0.01). Similarly, the clustered cardio-metabolic risk score was higher in SGA and LGA than AGA children (both P<0.05), and these differences among groups increased during adolescence (both P<0.05). Of note, a progression of the clustered cardio-metabolic risk score was observed from childhood to adolescence within SGA and within LGA subjects (both P<0.05).

Conclusions

SGA and LGA subjects showed an adverse cardio-metabolic profile during childhood when compared to AGA peers, with a worsening of this profile during adolescence. These findings indicate an overtime progression of insulin resistance and overall estimated cardiovascular risk from childhood to adolescence in SGA and LGA populations.

Natural history and clinical characteristics of CKD in type 1 and type 2 diabetes mellitus

The nature of CKD in diabetes is changing. Diabetic glomerulosclerosis remains the cause of CKD in most type 1 diabetic individuals. However, the rate of progression of diabetic nephropathy has slowed because of improving glucose and blood pressure control. Most individuals with type 2 diabetes and 5% to 30% of those with type 1 diabetes with progressive CKD have normal urine albumin excretion or low-level microalbuminuria (albumin-to-creatinine ratio approximately <100 mg/g), which does not progress despite the decline in glomerular filtration. People with progressive CKD but normal albuminuria have predominantly interstitial or vascular changes with much less glomerular changes. It seems likely that these histological abnormalities relate to blood pressure, aging, obesity, and intrarenal vascular disease. Initial studies suggested that 85% to 100% of diabetic individuals with microalbuminuria (Kidney Disease Improving Global Outcomes [KDIGO] CKD albuminuria A2) progressed to proteinuria (KDIGO CKD albuminuria A3). Recent data demonstrate that even after 2 to 3 years of persistent microalbuminuria, most will revert to normal albumin excretion (KDIGO CKD albuminuria A1). Regression is more likely at lower levels of microalbuminuria and with improved glucose, blood pressure, and lipid control. Thus, low levels of microalbuminuria cannot be considered as established diabetic nephropathy.

Obesity and kidney disease in type 1 and 2 diabetes: an analysis of the National Diabetes Audit

BACKGROUND

Obesity is increasingly prevalent in many countries. Obesity is a major risk factor for the development of type 2 diabetes but its relationship with diabetic kidney disease (DKD) remains unclear. Some studies have suggested that the metabolic syndrome (including obesity) may be associated with DKD in type 1 diabetes.

AIM

To investigate the association between obesity and DKD.

DESIGN

Retrospective cross-sectional study.

METHODS

National Diabetes Audit data were available for the 2007-08 cycle. Type 1 and 2 diabetes patients with both a valid serum creatinine and urinary albumin:creatinine ratio were included. DKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2), albuminuria or both. Logistic regression was used to analyse associations of obesity (body mass index ≥30 kg/m(2)) and other variables including year of birth, year of diagnosis, ethnicity and stage of kidney disease.

RESULTS

A total of 58 791 type 1 and 733 769 type 2 diabetes patients were included in the analysis. After adjustment, when compared with type 1 diabetes patients with normal renal function those with DKD were up to twice as likely to be obese. Type 2 DKD patients were also more likely to be obese. For example, type 2 diabetes patients with an eGFR <15 ml/min/1.73 m(2) and normoalbuminuria, microalbuminuria or macroalbuminuria were all more likely to be obese; odds ratios (95% CI) 1.65 (1.3-2.1), 1.56 (1.28-1.92) and 1.27 (1.05-1.54), respectively.

CONCLUSION

This study has highlighted a strong association between obesity and kidney disease in type 1 diabetes and confirmed their association in type 2 diabetes.

Diabetic nephropathy in type 1 diabetes: has the outlook improved since the 1980s?

This edition of Then and Now discusses three papers published in Diabetologia in the 1980s relating to diabetic nephropathy. Two epidemiological papers by Andersen et al (1983; 25:496-501) and Borch-Johnsen et al (1985; 28:590-596) described in graphic detail the ravages of diabetic nephropathy in type 1 diabetes. After 40 years of diabetes, 41% of their cohort had developed persistent proteinuria. The median time from first appearance of proteinuria to death was 7-8 years, the majority dying of uraemia or cardiovascular disease. The third paper, by Mathiesen et al (1984; 26:406-410), identified individuals with microalbuminuria, a much earlier stage of diabetic nephropathy, and analysed the risk of progression to persistent proteinuria at various levels of urine albumin excretion. Since the description of microalbuminuria, clinicians have hoped that earlier identification of individuals at high risk of end-stage kidney disease, coupled with aggressive use of reno-protective therapies, would prevent, or at the very least significantly delay, the development of end-stage renal disease. Recent data suggest that the outlook has indeed improved since the 1980s, at least in some populations. However, we may be delaying rather than preventing the development of microalbuminuria, proteinuria and kidney failure. Whilst a delay of 10 or more years in the appearance of end-stage renal disease is very welcome, further work is needed to understand why rates of chronic kidney disease vary substantially between cohorts and to develop novel therapies.

Maternal but not paternal association of ambulatory blood pressure with albumin excretion in young offspring with type 1 diabetes

OBJECTIVE

Familial predisposition to hypertension has been associated with the development of diabetic nephropathy in adults, but there are limited data in adolescents. Our aim was to assess whether parental ambulatory blood pressure (ABP) was associated with ABP and albumin excretion in young offspring with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Twenty-four-hour ABP monitoring was performed in 509 young offspring (mean +/- SD age 15.8 +/- 2.3 years) with type 1 diabetes, 311 fathers, and 444 mothers. Systolic (SBP) and diastolic blood pressure (DBP) measurements during 24 h, daytime, and nighttime were calculated. Three early morning urinary albumin-to-creatinine ratios (ACRs), A1C, and anthropometric parameters were available for the offspring.

RESULTS

All paternal ABP parameters, except for nighttime SBP, were independently related to the offspring's ABP (24-h SBP beta = 0.18, 24-h DBP beta = 0.22, daytime SBP beta = 0.25, daytime DBP beta = 0.23, and nighttime DBP beta = 0.18; all P < 0.01). Maternal 24-h DBP (beta = 0.19, P = 0.004), daytime DBP (beta = 0.09, P = 0.04), and nighttime SBP (beta = 0.24 P = 0.001) were related to the corresponding ABP parameter in the offspring. Significant associations were found between the offspring's logACR and maternal ABP. The association with 24-h DBP (beta = 0.16, P = 0.02), daytime DBP (beta = 0.16 P = 0.02), and nighttime DBP (beta = 0.15 P = 0.03) persisted even after adjustment for the offspring's ABP. Mothers of offspring with microalbuminuria had higher ABP than mothers of offspring without microalbuminuria (all P < 0.05).

CONCLUSIONS

In this cohort, parental ABP significantly influenced offspring blood pressure, therefore confirming familial influences on this trait. In addition, maternal ABP, particularly DBP, was closely related to ACR in the offspring, suggesting a dominant effect of maternal genes or an effect of the intrauterine environment on microalbuminuria risk.

Network of vascular diseases, death and biochemical characteristics in a set of 4,197 patients with type 1 diabetes (the FinnDiane Study)

Background

Cardiovascular disease is the main cause of premature death in patients with type 1 diabetes. Patients with diabetic kidney disease have an increased risk of heart attack or stroke. Accurate knowledge of the complex inter-dependencies between the risk factors is critical for pinpointing the best targets for research and treatment. Therefore, the aim of this study was to describe the association patterns between clinical and biochemical features of diabetic complications.

Methods

Medical records and serum and urine samples of 4,197 patients with type 1 diabetes were collected from health care centers in Finland. At baseline, the mean diabetes duration was 22 years, 52% were male, 23% had kidney disease (urine albumin excretion over 300 mg/24 h or end-stage renal disease) and 8% had a history of macrovascular events. All-cause mortality was evaluated after an average of 6.5 years of follow-up (25,714 patient years). The dataset comprised 28 clinical and 25 biochemical variables that were regarded as the nodes of a network to assess their mutual relationships.

Results

The networks contained cliques that were densely inter-connected (r > 0.6), including cliques for high-density lipoprotein (HDL) markers, for triglycerides and cholesterol, for urinary excretion and for indices of body mass. The links between the cliques showed biologically relevant interactions: an inverse relationship between HDL cholesterol and the triglyceride clique (r < -0.3, P < 10^-16), a connection between triglycerides and body mass via C-reactive protein (r > 0.3, P < 10^-16) and intermediate-density cholesterol as the connector between lipoprotein metabolism and albuminuria (r > 0.3, P < 10^-16). Aging and macrovascular disease were linked to death via working ability and retinopathy. Diabetic kidney disease, serum creatinine and potassium, retinopathy and blood pressure were inter-connected. Blood pressure correlations indicated accelerated vascular aging in individuals with kidney disease (P < 0.001).

Conclusion

The complex pattern of links between diverse characteristics and the lack of a single dominant factor suggests a need for multifactorial and multidisciplinary paradigms for the research, treatment and prevention of diabetic complications.

Effect of parental type 2 diabetes on offspring with type 1 diabetes

OBJECTIVE

The purpose of this study was to study the association between a parental history of type 2 diabetes and the metabolic profile as well as the presence of the metabolic syndrome and diabetes complications in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study design in 1,860 patients with type 1 diabetes from the Finnish Diabetic Nephropathy (FinnDiane) Study (620 patients with and 1,240 age-matched patients without a parental history of type 2 diabetes). Information on parental history was received from the type 1 diabetic offspring by a standardized questionnaire.

RESULTS

Patients with type 1 diabetes and a positive parental history of type 2 diabetes had a higher prevalence of the metabolic syndrome (44 vs. 38%; P = 0.013) and a metabolic profile related to insulin resistance (higher BMI, larger waist circumference, and higher triglycerides, A1C, and insulin dose per kilogram) and also had a later onset of type 1 diabetes (17.2 +/- 9.2 vs. 16.1 +/- 8.9 years; P = 0.008), which was also confirmed in the publicly available Diabetes Control and Complications Trial data set. In contrast, no association was observed with blood pressure, diabetes complications, or HLA genotype distribution. Parental history of type 2 diabetes was independently associated with age at onset of type 1 diabetes (odds ratio 1.02 [95% CI 1.01-1.03]), BMI (1.07 [1.02-1.12]), triglycerides (1.18 [1.03-1.35]), and insulin dose per kilogram (1.63 [1.04-2.54]).

CONCLUSIONS

Parental history of type 2 diabetes is associated with a later onset of type 1 diabetes, the metabolic syndrome, and a metabolic profile related to insulin resistance.

Metabolic phenotypes, vascular complications, and premature deaths in a population of 4,197 patients with type 1 diabetes

OBJECTIVE

Poor glycemic control, elevated triglycerides, and albuminuria are associated with vascular complications in diabetes. However, few studies have investigated combined associations between metabolic markers, diabetic kidney disease, retinopathy, hypertension, obesity, and mortality. Here, the goal was to reveal previously undetected association patterns between clinical diagnoses and biochemistry in the FinnDiane dataset.

RESEARCH DESIGN AND METHODS

At baseline, clinical records, serum, and 24-h urine samples of 2,173 men and 2,024 women with type 1 diabetes were collected. The data were analyzed by the self-organizing map, which is an unsupervised pattern recognition algorithm that produces a two-dimensional layout of the patients based on their multivariate biochemical profiles. At follow-up, the results were compared against all-cause mortality during 6.5 years (295 deaths).

RESULTS

The highest mortality was associated with advanced kidney disease. Other risk factors included 1) a profile of insulin resistance, abdominal obesity, high cholesterol, triglycerides, and low HDL(2) cholesterol, and 2) high adiponectin and high LDL cholesterol for older patients. The highest population-adjusted risk of death was 10.1-fold (95% CI 7.3-13.1) for men and 10.7-fold (7.9-13.7) for women. Nonsignificant risk was observed for a profile with good glycemic control and high HDL(2) cholesterol and for a low cholesterol profile with a short diabetes duration.

CONCLUSIONS

The self-organizing map analysis enabled detailed risk estimates, described the associations between known risk factors and complications, and uncovered statistical patterns difficult to detect by classical methods. The results also suggest that diabetes per se, without an adverse metabolic phenotype, does not contribute to increased mortality.