Increasing urine albumin excretion is associated with growth hormone hypersecretion and reduced clearance of insulin in adolescents and young adults with type 1 diabetes: the Oxford Regional Prospective Study

Neurodevelopmental Disorders, Glycemic Control, and Diabetic Complications in Type 1 Diabetes: a Nationwide Cohort Study

CONTEXT

Neurodevelopmental disorders are more prevalent in childhood-onset type 1 diabetes than in the general population, and the symptoms may limit the individual's ability for diabetes management.

OBJECTIVE

This study investigated whether comorbid neurodevelopmental disorders are associated with long-term glycemic control and risk of diabetic complications.

METHODS

This population-based cohort study used longitudinally collected data from Swedish registers. We identified 11 326 individuals born during 1973-2013, diagnosed with type 1 diabetes during 1990-2013 (median onset age: 9.6 years). Among them, 764 had a comorbid neurodevelopmental disorder, including attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, and intellectual disability. We used multinomial logistic regression to calculate odds ratios (ORs) of having poor glycemic control (assessed by glycated hemoglobin [HbA1c]) and Cox regression to estimate hazard ratios (HRs) of nephropathy and retinopathy.

RESULTS

The median follow-up was 7.5 years (interquartile range [IQR] 3.9, 11.2). Having any neurodevelopmental disorder (ORadjusted 1.51 [95% CI 1.13, 2.03]), or ADHD (ORadjusted 2.31 [95% CI 1.54, 3.45]) was associated with poor glycemic control (mean HbA1c > 8.5%). Increased risk of diabetic complications was observed in patients with comorbid neurodevelopmental disorders (HRadjusted 1.72 [95% CI 1.21, 2.44] for nephropathy, HRadjusted 1.18 [95% CI 1.00, 1.40] for retinopathy) and patients with ADHD (HRadjusted 1.90 [95% CI 1.20, 3.00] for nephropathy, HRadjusted 1.33 [95% CI 1.07, 1.66] for retinopathy). Patients with intellectual disability have a particularly higher risk of nephropathy (HRadjusted 2.64 [95% CI 1.30, 5.37]).

CONCLUSION

Comorbid neurodevelopmental disorders, primarily ADHD and intellectual disability, were associated with poor glycemic control and a higher risk of diabetic complications in childhood-onset type 1 diabetes.

A review of renal GH/IGF1 family gene expression in chronic kidney diseases

Despite decades of study on the contribution of growth hormone (GH) to the development of kidney disease, there remains the question of the relative contribution of elevated levels of GH to kidney damage in humans, particularly in diabetic nephropathy occurring in type 1 patients. In this study, we reviewed several publicly available datasets to examine transcription of twelve genes associated with the GH/IGF1 axis in several types of human and rodent kidney diseases. Our analyses revealed downregulation of renal GHR and IGF1 gene expression in several different chronic human kidney diseases, including diabetic nephropathy, with general upregulation of IGFBP6 in the same tissues and diseases. These findings were generally supported by a review of studies in rodent models. In healthy and diseased human kidneys, increased GHR gene expression was associated with increases in glomerular filtration rate (GFR) and decreases in serum creatinine. IGFBP6 gene expression demonstrated the opposite clinical correlation. Our results suggest the kidney may exhibit GH insensitivity due to low GHR gene expression during most chronic kidney diseases.

A new strategy for vascular complications in young people with type 1 diabetes mellitus

Diabetes vascular complications, including cardiovascular disease, diabetic nephropathy and retinopathy, have a negative effect on the long-term prognosis of young people with type 1 diabetes mellitus (T1DM). Poor glycaemic control and consequent increased HbA_1c levels are major risk factors for the development of vascular complications. HbA_1c levels are the main focus of current management strategies; however, the recommended target is rarely achieved in adolescents. Thus, a clear need exists for improved biomarkers to identify high-risk young people early and to develop new intervention strategies. Evidence is accumulating that early increases in urinary albumin excretion could be predictive of adolescents with T1DM who are at an increased risk of developing vascular complications, independent of HbA_1c levels. These findings present an opportunity to move towards the personalized care of adolescents with T1DM, which takes into consideration changes in albumin excretion and other risk factors in addition to HbA_1c levels.

Banting Memorial Lecture 2016 Reducing lifetime risk of complications in adolescents with Type 1 diabetes

Adolescence is a challenging period of life for any young person, and for those with Type 1 diabetes, physiological and psychological factors can result in a deterioration in glycaemic control. In young people with Type 1 diabetes, puberty may be an additional risk factor impacting on the lifetime risk for renal and cardiovascular complications. Our longitudinal studies have identified that increases in urinary albumin excretion through childhood are associated with the development of microalbuminuria and a generalized endotheliopathy linked to cardiovascular risk. Screening of participants recruited to the Adolescent type 1 Diabetes cardio-renal Intervention Trial (AdDIT) confirms that these early changes in albumin excretion are related to both diabetic nephropathy and cardiovascular risk; in part, independent of glycaemic control. Thus, as well as current attempts to improve glycaemic control through enhanced targeted insulin delivery, pumps, sensors and closed loop, we have explored the role of angiotensin-converting enzyme inhibitors and statins in providing cardio-renal protection during adolescence.

The contribution of glycemic control to impaired growth during puberty in young people with type 1 diabetes and microalbuminuria

BACKGROUND

In adults with type 1 diabetes (T1D), short stature has been associated with risk for cardiovascular disease and nephropathy. However, there are no available data on the potential relationship between growth patterns during puberty and the development of vascular complications. Our aim was to assess whether pubertal growth is impaired in young people with T1D who develop microalbuminuria (MA).

METHODS

Repeated height measurements performed during adolescence were available for 206 young people (107 boys) with T1D followed in the Oxford Regional Prospective Study. Longitudinal data on albumin-creatinine ratios and hemoglobin A1c (HbA1c) were also collected from the study participants. Height standard deviations score (SDS) was compared between subjects with (MA+; n = 66) and without MA (MA-; n = 140).

RESULTS

In the group as a whole, mean [95% CI] height SDS progressively declined during puberty, from 0.145 [0.015; 0.274] to -0.003 [-0.145; 0.138], p < 0.001. However, the decline in height SDS was significantly different between the MA+ and MA- groups (p = 0.023), with a mean difference in final height of 4.29 [1.87; 6.72] cm, p = 0.001. Final height was inversely associated with MA (HR [95%CI]: 0.942 [0.908; 0.979], p = 0.002), although this association was no longer significant after adjusting for HbA1c, which was higher in the MA+ group.

CONCLUSION

In this study, we found a significant impairment in growth during puberty in young people with T1D, particularly in those developing MA. Poor glycemic control as well as other genetic or environmental factors could explain these associations.

The glomerular podocyte as a target of growth hormone action: implications for the pathogenesis of diabetic nephropathy

Involvement of the growth hormone (GH) / insulin-like growth factor 1 (IGF-I) axis in the pathogenesis of diabetic nephropathy (DN) is strongly suggested by studies investigating the impact of GH excess and deficiency on renal structure and function. GH excess in both the human (acromegaly) and in transgenic animal models is characterized by significant structural and functional changes in the kidney. In the human a direct relationship has been noted between the activity of the GH/IGF-1 axis and renal hypertrophy, microalbuminuria, and glomerulosclerosis. Conversely, states of GH deficiency or deficiency or inhibition of GH receptor (GHR) activity confer a protective effect against DN. The glomerular podocyte plays a central and critical role in the structural and functional integrity of the glomerular filtration barrier and maintenance of normal renal function. Recent studies have revealed that the glomerular podocyte is a target of GH action and that GH's actions on the podocyte could be detrimental to the structure and function of the podocyte. These results provide a novel mechanism for GH's role in the pathogenesis of DN and offer the possibility of targeting the GH/IGF-1 axis for the prevention and treatment of DN.

Occurrence of microalbuminuria in young people with Type 1 diabetes: importance of age and diabetes duration

AIMS

To determine the occurrence of microalbuminuria in young people with Type 1 diabetes mellitus followed prospectively for 2 years and to relate the presence of persistent elevations in urinary albumin excretion (UAE) to age, diabetes duration, puberty and other factors.

METHODS

During a 2 year period, random urine samples were obtained from 471 patients, aged 8-18 years (mean +/-sd 12.9 +/- 2.3 years) with Type 1 diabetes duration 5.6 +/- 3.0 years, as part of routine clinical care. Urine albumin and creatinine concentrations were measured in 1310 samples (median, 3 samples per patient) and the albumin:creatinine ratio was calculated (in micrograms albumin per milligram creatinine). Height, weight, blood pressure (BP), glycated haemoglobin (HbA(1c)), blood glucose monitoring frequency and Tanner staging were collected from patients' medical records.

RESULTS

Twenty-three per cent of patients had one or more sample with elevated UAE (> or =20 microg/mg) and 9.3% had persistent elevations (> or =2 samples > or =20 microg/mg). Those with and without persistent microalbuminuria did not differ significantly in age, diabetes duration, z-score for body mass index, pubertal status or BP percentile. Ten per cent of children <13 years old and 9% of children > or =13 years old had persistent microalbuminuria. Persistent microalbuminuria was significantly associated with diabetes duration only in older children (duration 0.5-3 years, 4%; 4-6 years, 8%; > or =7 years, 14%; P = 0.02, trend test). Mean HbA(1c) over the 2 years was 8.7 +/- 1.2%. In a logistic regression model, mean HbA(1c) was the only significant predictor of persistent microalbuminuria (odds ratio 1.3, 95% confidence interval 1.0-1.6, P = 0.05).

CONCLUSIONS

Microalbuminuria in older children with Type 1 diabetes is likely to be clinically significant. In younger children, it may reflect functional, reversible renal changes. Longitudinal analysis is needed to confirm the probable transient nature of microalbuminuria in young patients with Type 1 diabetes.

The development of microalbuminuria is associated with raised longitudinal adiponectin levels in female but not male adolescent patients with type 1 diabetes

AIMS/HYPOTHESIS

We determined the longitudinal relationship between adiponectin levels and the development of microalbuminuria in an inception cohort of children with type 1 diabetes.

METHODS

Blood samples collected annually over a median of 9.0 (range 1.3-14.9) years were assayed for adiponectin and HbA(1c) in 55 children (36 girls) with type 1 diabetes and microalbuminuria whose age of onset of diabetes was 9.4 years (range 2.2-15.4). Samples were also assayed from normoalbuminuric children (controls) matched for age, sex and duration of diabetes.

RESULTS

Overall, adiponectin levels were higher in girls than in boys, but only after 11 years of age (median [range]: 15.3 [5.8-124.4] vs 11.6 [4.1-26.5] mg/l, p < 0.001). Furthermore, adiponectin levels were higher in girls with microalbuminuria than in control girls, but this was only apparent after the onset of microalbuminuria (p = 0.001, adjusted for BMI, daily insulin dose, HbA(1c) and age). In boys, adiponectin levels did not differ between those with microalbuminuria and controls. Further sex-related discordant associations with adiponectin levels were observed; in girls, adiponectin levels were positively related to HbA(1c) levels (r = 0.2, p = 0.05) and urine albumin excretion (r = 0.3, p < 0.05) and inversely related to BMI (r = -0.2, p < 0.05). These associations were absent in boys.

CONCLUSIONS/INTERPRETATION

In adolescent girls with type 1 diabetes but not in boys, adiponectin levels increase with increasing urine albumin excretion and onset of microalbuminuria. Although causal links cannot be inferred, this sexual dimorphism may reflect interactive effects of hyperglycaemia and sex steroids on risk of complications and adiponectin production.

Diabetic nephropathy in children and adolescents

Type 1 diabetes mellitus (T1DM) commonly occurs in childhood or adolescence, although the rising prevalence of type 2 diabetes mellitus (T2DM) in these age groups is now being seen worldwide. Diabetic nephropathy (DN) develops in 15-20% of subjects with T1DM and in similar or higher percentage of T2DM patients, causing increased morbidity and premature mortality. Although overt DN or kidney failure caused by either type of diabetes are very uncommon during childhood or adolescence, diabetic kidney disease in susceptible patients almost certainly begins soon after disease onset and may accelerate during adolescence, leading to microalbuminuria or incipient DN. Therefore, all diabetics warrant ongoing assessment of kidney function and screening for the earliest manifestations of renal injury. Pediatric health care professionals ought to understand about risk factors, strategy for prevention, method for screening, and treatment of early DN. This review considers each form of diabetes separately, including natural history, risk factors for development, screening for early manifestations, and strategy recommended for prevention and treatment of DN in children and adolescents.

An IGF-I gene polymorphism modifies the risk of developing persistent microalbuminuria in type 1 diabetes

OBJECTIVE

Derangements of the GH-IGF-I axis have been associated with microalbuminuria (MA) in type 1 diabetes. The aim of this study was to investigate whether an IGF-I gene promoter polymorphism influenced the development of persistent MA in type 1 diabetes.

DESIGN

A prospective follow-up study of a cohort of 277 patients with newly diagnosed type 1 diabetes consecutively enrolled between September 1979 and August 1984.

METHODS

Urinary albumin excretion rate over 24 h was measured in each patient at least once a year. Persistent MA was defined as a urinary albumin excretion rate between 30 and 300 mg/24 h.

RESULTS

During a median follow-up of 18.0 years (range 1.0-21.5), 79 of 277 patients developed persistent MA. IGF-I gene genotype was available for 216 subjects; in 73% of the subjects, the wild-type genotype of this IGF-I gene polymorphism was present, while 27% had the variant type. At baseline, there were no differences in IGF-I levels and HbA(1c) values between subjects with the wild type and subjects with variant type. By Kaplan-Meier analysis, subjects with the variant type of this polymorphism had during follow-up a higher risk of development of MA compared subjects with the wild type (P = 0.03).

CONCLUSIONS

Subjects with the variant type of an IGF-I gene polymorphism had a significantly increased risk of developing MA. This risk was not mediated through changes in circulating IGF-I levels. Our study suggests that in type 1 diabetes, this IGF-I gene polymorphism is a risk factor of MA.

Short-term suppression of elevated growth hormone concentrations following insulin-like growth factor 1 administration in young adults with type 1 diabetes does not alter glomerular filtration or albumin excretion rates

OBJECTIVE

Young adults with type 1 diabetes mellitus (T1DM) have increased glomerular filtration rate (GFR), which may mediate progressive renal disease and microalbuminuria. This may be secondary to low concentrations of insulin-like growth factor (IGF)-I and GH hypersecretion. We tested the hypothesis that restoration of circulating IGF-I concentrations in young adults with T1DM might suppress GH secretion, GFR and urinary albumin excretion.

DESIGN

In a randomized double blind crossover study six young adults with T1DM (three men, 19-24 years) received 7 days treatment with rhIGF-I/insulin-like growth factor binding protein (IGFBP)-3 complex (SomatoKine) 0.4 mg/kg/day and placebo. Subjects underwent overnight insulin infusion for euglycaemia, followed by determination of GFR and albumin excretion rate.

RESULTS

Following IGF-I/IGFBP-3 complex, overnight insulin requirements (0.15 vs placebo 0.21 mU/kg/min, P < 0.04), plasma insulin (77 vs placebo 152 pmol/l, P < 0.01) and mean overnight GH (2.6 vs placebo 4.8 mU/l, P < 0.04) fell. IGF-I (492 vs placebo 218 ng/ml, P < 0.01) and IGFBP-3 (4.5 vs placebo 3.9 microg/ml, P < 0.05) increased. GFR did not change (145.5 (23.9) ml/min/1.73 m(2) post-IGF-I/IGFBP-3 complex vs 152.2 (19.8) post placebo). Albumin excretion rate did not change 9.5 (5.5-16.6)mg/24 h pre- vs 11.5 (9.9-20.2) post-IGF-I/IGFBP-3 complex and 10.7 (8.1-21.2) pre- vs 11.5 (8.7-29.9) post placebo. Plasma creatinine levels were lower following IGF-I/IGFBP-3 complex (mean +/- SD, 56.2 +/- 16.8 micromol/l) vs placebo (61.5, 45.0, P < 0.02).

CONCLUSIONS

Seven days treatment with IGF-I/IGFBP-3 complex enhanced overnight insulin sensitivity and reduced GH levels, but there was no effect on glomerular hyperfiltration or albumin excretion rates.

Natural history and risk factors for microalbuminuria in adolescents with type 1 diabetes: a longitudinal study

OBJECTIVE

To describe the natural history and risk factors for persistent microalbuminuria in children and adolescents with type 1 diabetes followed for up to 15 years.

RESEARCH DESIGN AND METHODS

This study contained a longitudinal cohort of 972 patients; analysis of baseline risk factors was performed using logistic regression and predictors over time using survival analysis. Albumin excretion rate was measured on three consecutive timed overnight urine collections on at least two occasions. Normoalbuminuria was defined as a median albumin excretion rate < 7.5 microg/min, borderline microalbuminuria as 7.5-20 microg/min, and microalbuminuria as 20-200 microg/min. Microalbuminuria was further classified as persistent if its duration was >12 months. Median age was 12.7 years (interquartile range 11.5-14.4) and diabetes duration 6.5 years (4.1-9.3) at first assessment, and median follow-up was 6.2 years (range 1-15.3).

RESULTS

The incidence of persistent microalbuminuria was 4.6 (95% CI 3.3-6.1) per 1,000 patient-years. Predictors of persistent microalbuminuria from the first assessment using multiple logistic regression were high cholesterol (odds ratio 2.2 [95% CI 1.2-4.0]) and borderline microalbuminuria (2.5 [1.2-5.2]). Predictors using Cox regression were HbA(1c) (hazard ratio 1.4 [95% CI 1.1-1.7]), age at diagnosis (1.2 [1.1-1.3]), obesity (3.6 [0.8-15.5]), and insulin dose (2.7 [1.0-7.5]).

CONCLUSIONS

Children and adolescents with type 1 diabetes who have borderline microalbuminuria are more than twice as likely to develop persistent microalbuminuria. In addition to poor glycemic control, clinical markers of insulin resistance were associated with an increased risk of microalbuminuria.

Growth hormone hypothesis and development of diabetic nephropathy in Type 1 diabetes

In Type 1 diabetes, poor glycemic control is the key predictor for the development of microalbuminuria, an established early marker of overt nephropathy. However, the role of other pathways in the development of diabetic nephropathy may also be important. The growth hormone (GH) hypothesis suggests that the GH-insulin-like growth factor (IGF)-1 axis may play an important role in this disease process. In Type 1 diabetes, the characteristic pattern of GH hypersecretion and low circulating IGF-1 levels results from hepatic GH resistance owing to the lack of portal insulin. Clinical data indicate that high GH and low IGF-1 levels reduce insulin sensitivity and worsen glycemic control. Furthermore, despite hepatic GH resistance, GH receptors at the kidney remain intact. Experimental data show that excess GH stimulates renal GH receptors and, through paracrine IGF-1 production, results in pathophysiological changes consistent with diabetic nephropathy, namely nephromegaly, glomerular hyperfiltration and eventual proteinuria. These abnormalities are reversed by intervention to block or normalize the local effects of GH and IGF-1. Although such data in humans are limited, preliminary trials show that interventions to increase IGF-1 levels and reduce GH hypersecretion improve glycemic control and insulin sensitivity in the short term. However, their effects on early nephropathy and end points, such as the prevalence of end stage renal disease, have yet to be determined.

Longitudinal relation between limited joint mobility, height, insulin-like growth factor 1 levels, and risk of developing microalbuminuria: the Oxford Regional Prospective Study

AIMS

To determine risk factors for development of microalbuminuria (MA) in relation to detection of limited joint mobility (LJM+) of the interphalangeal joints in a longitudinal cohort of type 1 diabetic (T1DM) subjects.

METHODS

A total of 479 T1DM subjects diagnosed <16 years were followed from diagnosis of diabetes with annual assessments consisting of assessment of LJM, measurement of HbA1c and insulin-like growth factor 1 (IGF-1), and three urine samples for albumin:creatinine ratio (ACR).

RESULTS

After a median follow up of 10.9 years, 162 subjects (35.1%) developed LJM at median age 13.0 years and duration 5.2 years. More subjects developed LJM after compared to before puberty (67.6 v 32.4%). In LJM+ compared to LJM- subjects, HbA1c (mean 10.1 (SD 1.6) v 9.6 (1.4) %)) and ACR levels (median 1.1 (range 0.2-242.9) v 0.9 (0.4-70.7) mg/mmol) were higher, and in a Cox model probability of developing LJM was related to puberty and higher HbA1c levels. ACR levels were higher after detection of LJM compared to before (median 1.2 (range 0.4-102.6) v 0.8 (0.2-181.9) mg/mmol). Probability of developing MA was related to puberty, HbA1c, female sex, and presence of LJM (a 1.9-fold increased risk). Both LJM and MA were associated with lower height SDS (LJM: mean 0.0 (SD 1.0) v 0.2 (1.1); MA: 0.0 (1.0) v 0.2 (SD 1.0)) and lower IGF-1 levels.

CONCLUSION

The development of LJM was associated with an increased risk of microalbuminuria, independent of glycaemic control. Risk for both microalbuminuria and LJM was associated with puberty, reduced growth, and reduced IGF-1 levels, and may indicate underlying shared pathogenic mechanisms.

The relationship between microalbuminuria and glomerular filtration rate in young type 1 diabetic subjects: The Oxford Regional Prospective Study

BACKGROUND

The purpose of this study was to examine the relationship between glomerular filtration rate (GFR) measured at 5 years' diabetes duration and annual urine albumin excretion in a prospective cohort of children with type 1 diabetes (T1DM).

METHODS

Three hundred and eight children were followed from diagnosis of T1DM [aged 9.8 years (range 0.4-15.9) for a median duration of 10.9 years (6.0-17.8) with annual assessments comprising measurement of HbA1(c) and 3 urine samples for albumin:creatinine ratio (ACR). GFR was measured in all children at 5 years' diabetes duration.

RESULTS

Two hundred forty-three (78.8%) subjects were normoalbuminuric (MA-) for the duration of the study. At 5 years: 35 (11.4%) subjects had MA (MA+) and 30 (9.7%) subjects were normoalbuminuric but developed MA during subsequent follow-up annual assessments (future MA+). In the future MA+ group compared to the MA+ and MA- groups; GFR was higher (167 vs. 134 vs. 139 mL/min/1.73 m(2), P < 0.002); the prevalence of hyperfiltration (GFR >125 mL/min/1.73 m(2)) was greater (97 vs. 57 vs. 64%, P= 0.006) and HbA1c levels were higher (11.4 vs. 10.8 vs. 9.7%, P < 0.001). The probability (Cox Model) of having hyperfiltration at 5 years' duration was related to puberty (a 1.7-fold increased risk with puberty onset) and poor glycemic control (a 10% increased risk for a 1% increase in HbA1c). Comparing subjects with and without hyperfiltration, prior to the first GFR measurement no difference in ACR levels existed; however, after this time median ACR levels were significantly greater [1.2 (0.1-86.4) vs. 0.9 (0.1-71.6) mg/mmol, P= 0.003], independent of age and HbA1c levels. The probability of developing MA between 5 and 10 years' duration was associated with poor glycemic control (a 30% increased risk for a 1% increase in HbA1c) and higher GFR at 5 years (22% increased risk for a 10 mL/min/1.73 m(2) rise in GFR).

CONCLUSION

Glomerular hyperfiltration is associated with puberty and increasing ACR levels and is predictive of MA independent of HbA1c. This suggests that factors other than poor glycemic control may be involved in the pathogenesis of early diabetic nephropathy and early intervention with medical therapy to reduce GFR may be beneficial even before onset of MA.