Retinal arteriolar tortuosity is associated with retinopathy and early kidney dysfunction in type 1 diabetes

PURPOSE

To examine the association of retinal vessel tortuosity with diabetic retinopathy and early nephropathy in type 1 diabetes.

DESIGN

Cross-sectional.

METHODS

A total of 1159 participants with type 1 diabetes aged 12 to 20 years, attending diabetes clinics in Children's Hospital at Westmead, Sydney, Australia between 1990 and 2002, were included. Retinal photography and clinical examinations were performed during the baseline visit to assess diabetic retinopathy and albumin excretion rate (AER). Retinal vessel tortuosity was measured from digitized retinal photographs using a semi-automated computer program by a single grader masked to participants' characteristics. Diabetic retinopathy was defined as ETDRS level ≥21 (mild nonproliferative retinopathy) and early kidney dysfunction was defined as AER ≥7.5 μg/min.

RESULTS

Of 944 patients (81.4%), 85 (9.0%) had signs of retinopathy only, 250 (26.5%) had early kidney dysfunction only, and 85 (9.0%) had both retinopathy and early kidney dysfunction. In multivariate analysis, higher arteriolar tortuosity was associated with retinopathy (odds ratio [OR] 2.01, 95% confidence interval [CI] 1.23-3.29, the highest quartile vs the remaining 3 quartiles), early kidney dysfunction (OR 1.56, 95% CI 1.06-2.28, per standard deviation [SD] increase), or coexistence of both complications (OR 1.96, 95% CI 1.21-3.24, the highest quartile vs the remaining 3 quartiles).

CONCLUSIONS

Greater retinal arteriolar tortuosity was independently associated with retinopathy and early stage of nephropathy in type 1 diabetes. These findings may offer the potential of quantitative measurement of retinal vessel tortuosity for diabetic complication risk assessment.

Microvascular complications assessment in adolescents with 2- to 5-yr duration of type 1 diabetes from 1990 to 2006

OBJECTIVE

Microvascular complications occur in adolescents with type 1 diabetes, although guidelines vary as to when screening should commence and prevalence data for those with ≤5-yr duration are limited. We therefore investigated trends in prevalence of early microvascular complications over 17 yr.

RESEARCH DESIGN AND METHODS

819 adolescents (54% female) aged 11-17 yr with 2- to 5-yr diabetes duration were assessed for complications at a tertiary pediatric diabetes clinic between 1990 and 2006. Early retinopathy was detected using seven-field fundal photography, albumin excretion rate (AER) by timed overnight urine collections and peripheral nerve function by thermal/vibration threshold at the foot. Results were analyzed by age, time period of assessment, and duration.

RESULTS

Early retinopathy declined from 1990 to 2002 (16-7%, p < 0.01), then remained unchanged until 2006. Early elevation of AER (≥7.5 µg/min) and microalbuminuria (≥20 µg/min) did not change over time, whereas peripheral nerve abnormalities increased (14-28%, p < 0.01). Median hemoglobin A1c improved (8.7-8.2%, p < 0.01), in parallel with increased total daily insulin dose and injections per day (p < 0.01). Body mass index standard deviation score increased over time (0.55-0.79, p < 0.01). In multivariate logistic regression, early retinopathy was associated with earlier time period [odds ratio (OR) 0.68, confidence interval (CI) 0.55-0.85, p < 0.01] and older age (OR 1.19, CI 1.02-1.39, p = 0.03). AER ≥ 7.5 µg/min was associated with older age (1.19, 1.06-1.34, p < 0.01) and longer diabetes duration (OR 1.28, CI 1.02-1.62, p = 0.04) and height-adjusted peripheral nerve abnormalities with later time period (OR 1.26, CI 1.05-1.50, p = 0.01).

CONCLUSIONS

Early complications are not uncommon in adolescents with 2- to 5-yr diabetes duration, despite more intensive management in recent years.

Continued reduction in the prevalence of retinopathy in adolescents with type 1 diabetes: role of insulin therapy and glycemic control

OBJECTIVE

To examine trends in microvascular complications in adolescents with type 1 diabetes between 1990 and 2009 in Sydney, Australia.

RESEARCH DESIGN AND METHODS

We used analysis of complications in 1,604 adolescents (54% female, aged 12-20 years, median duration 8.6 years), stratified by four time periods using Generalized Estimation Equations as follows: T1 (1990-1994), T2 (1995-1999), T3 (2000-2004), and T4 (2005-2009). Early retinopathy was detected using seven-field fundal photography, albumin excretion rate (AER) using timed overnight urine collections, and albumin-to-creatinine ratio (ACR) and peripheral nerve function using thermal and vibration threshold.

RESULTS

Retinopathy declined (53, 38, 23, and 12%; P < 0.001), as did borderline elevation of AER/ACR (45, 30, 26, and 30%; P < 0.001) and microalbuminuria (8, 4, 3, and 3%; P = 0.006). Multiple daily injections (MDI)/continuous subcutaneous insulin infusion (CSII) use increased (17, 54, 75, and 88%; P < 0.001), median HbA(1c) decreased (9.1, 8.9, 8.5, and 8.5%; P < 0.001), and severe hypoglycemia was unchanged (6, 8, 10, and 7%; P = 0.272). Retinopathy was associated with diabetes duration (odds ratio [OR] 1.12 [95% CI 1.08-1.17]), age (1.13 [1.06-1.20]), HbA(1c) (1.16 [1.08-1.25]), systolic blood pressure (BP) SDS (1.31 [1.16-1.48]), socioeconomic disadvantage (1.42 [1.04-1.95]), and 1 to 2 injections per day (vs. MDI/CSII; 1.35 [1.05-1.73]); borderline AER/ACR with male sex (1.32 [1.02-1.70]), age (1.19 [1.12-1.26]), HbA(1c) (1.18 [1.08-1.29]), weight SDS (1.31 [1.21-1.53]), insulin dose per kilograms (1.64 [1.13-2.39]), 1 to 2 injections per day (1.41 [1.08-1.84]), and socioeconomic disadvantage (1.68 [1.23-2.31]); and microalbuminuria with age (1.14 [1.01-1.29]), HbA(1c) (1.20 [1.05-1.37]), diastolic BP SDS (1.76 [1.26-2.46]), and 1 to 2 injections per day (1.95 [1.11-3.41]).

CONCLUSIONS

The decline in retinopathy supports contemporary guidelines that recommend lower glycemic targets and use of MDI/CSII in children and adolescents with type 1 diabetes.

Managing ethically questionable parental requests: growth suppression and manipulation of puberty

Doctors sometimes struggle with ethically challenging requests for treatment from children's parents. For instance, we have recently had two requests by parents of children, a girl and a boy, each with a severe developmental disability, for hormonal therapy to suppress growth and puberty: the girl's parents requested, in addition, hysterectomy and mastectomy. We propose a reliable approach to assessing the ethical and legal aspects of these and other requests for 'non-therapeutic' treatment of a minor who lacks the capacity to give informed consent. We argue that a doctor should first assess whether the request is one that he or she can, in conscience, accede to, and then, if it is, seek the authorisation of a court. We outline considerations relevant to the doctor's assessment of both the ethical issues and to the need for court authorisation.

Retinal vascular geometry predicts incident retinopathy in young people with type 1 diabetes: a prospective cohort study from adolescence

OBJECTIVE

To examine the association between retinal vascular geometry and subsequent development of incident retinopathy in young patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

A prospective cohort study of 736 people with type 1 diabetes aged 12 to 20 years, retinopathy-free at baseline, attending an Australian tertiary care hospital. Retinopathy was determined from seven-field retinal photographs according to the modified Airlie House Classification. Retinal vascular geometry, including length/diameter ratio (LDR) and simple tortuosity (ST), was quantified in baseline retinal photographs. Generalized estimating equations were used to determine risk of retinopathy associated with baseline LDR and ST, adjusting for other factors.

RESULTS

After a median 3.8 (interquartile range 2.4-6.1) years of follow-up, incident retinopathy developed in 287 of 736 (39%). In multivariate analysis, lower arteriolar LDR (odds ratio 1.8 [95% CI 1.2-2.6]; 1st vs. 4th quartile) and greater arteriolar ST (1.5 [1.0-2.2]; 4th vs. 1st quartile) predicted incident retinopathy after adjusting for diabetes duration, sex, A1C, blood pressure, total cholesterol, and BMI. In subgroup analysis by sex, LDR predicted incident retinopathy in male and female participants (2.1 [1.1-4.0] and 1.7 [1.1-2.7]; 1st vs. 4th quartiles, respectively) and greater arteriolar ST predicted incident retinopathy in male participants (2.4 [1.1-4.4]; 4th vs. 1st quartile) only.

CONCLUSIONS

Lower arteriolar LDR and greater ST were independently associated with incident retinopathy in young people with type 1 diabetes. These vascular geometry measures may serve as risk markers for diabetic retinopathy and provide insights into the early structural changes in diabetic microvascular complications.

Vitamin D deficiency is associated with retinopathy in children and adolescents with type 1 diabetes

OBJECTIVE

To examine the hypothesis that vitamin D deficiency (VDD) is associated with an increased prevalence of microvascular complications in young people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

In a cross-sectional study of 517 patients, 25-hydroxyvitamin D was measured. Retinopathy was assessed by 7-field stereoscopic retinal photography, peripheral neuropathy by thermal and vibration threshold testing, and microalbuminuria by albumin excretion rate or albumin-to-creatinine ratio.

RESULTS

Retinopathy prevalence was higher in cases with VDD versus sufficiency (18 vs. 9%, P = 0.02); deficiency was not associated with microalbuminuria or neuropathy. In logistic regression, retinopathy was associated with VDD (odds ratio 2.12 [95% CI 1.03-4.33]), diabetes duration (1.13, 1.05-1.23), and HbA(1c) (1.24, 1.02-1.50).

CONCLUSIONS

VDD is associated with an increased prevalence of retinopathy in young people with type 1 diabetes. The inflammatory and angiogenic effects of VDD may contribute to early retinal vascular damage; however, further investigations are warranted.

Complications of childhood diabetes and the role of technology

Technology for detecting vascular complications of childhood diabetes has already helped many children and youth by allowing for the early detection and intervention of impending or present problems as the result of the diabetes state. Prior to the advent of screening, young people developed clinical disease, in particular visual loss and renal impairment that often rapidly progressed to end-stage disease. With the advent of laser photocoagulation, which dramatically reduced visual loss from diabetic retinopathy, the importance of early detection and treatment of micro and macrovascular complications prior to clinical symptoms became apparent. Many technological advances are now being applied to the pediatric diabetes population, in either clinical care or the research setting. For example, retinal photography makes screening more accessible and more meaningful to adolescents with diabetes and can be used in large screening programs, for teleophthalmology, clinical trials and in geographically remote areas. Quantitative measures used to assess microvascular structure may be useful in monitoring interventions in the future. Quantitative sensory tests can monitor nerve dysfunction, but evaluations such as intraepidermal nerve fibre pathology and cornea confocal microscopy may be more sensitive to diagnose neuropathic complications in youth. B-mode ultrasonography can assess vascular function by measuring endothelium-dependent flow mediated dilatation and changes in the intima-media thickness of the carotid and aorta. It is the purpose of this manuscript to explore the role of present and future technological advances (Table 1) in young people with diabetes.

Cystic fibrosis-related diabetes in children--gaps in the evidence?

As the life span of patients with cystic fibrosis has increased, so has the prevalence of cystic fibrosis-related diabetes mellitus. However, screening practices for cystic fibrosis-related diabetes mellitus vary widely, which affects accurate estimates of the health burden of this comorbidity. The management of prediabetes and hyperglycemia is an increasingly important aspect of care in patients with cystic fibrosis, but few studies have specifically addressed the management of cystic fibrosis-related diabetes mellitus. Previous studies support the use of insulin for the treatment of patients with this disorder, but the evidence for its use in patients with cystic fibrosis and impaired glucose tolerance is poor. Nutritional management is currently guided by dietary recommendations for individuals with cystic fibrosis, with little evidence specific to the dietary management of patients with cystic fibrosis-related diabetes mellitus. Additionally, microvascular complications have become more frequent as a result of the rise in life expectancy of these patients, yet to date no intervention studies have addressed prevention or management of diabetic complications in patients with cystic fibrosis. A strong evidence base is needed to guide the management of patients with cystic fibrosis-related diabetes mellitus and its complications.

Alterations in retinal microvascular geometry in young type 1 diabetes

OBJECTIVE

To describe retinal microvascular geometric parameters in young patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Patients with type 1 diabetes (aged 12-20 years) had clinical assessments and retinal photography following standardized protocol at a tertiary-care hospital in Sydney. Retinal microvascular geometry, including arteriolar and venular tortuosity, branching angles, optimality deviation, and length-to-diameter ratio (LDR), were measured from digitized photographs. Associations of these geometric characteristics with diabetes duration, A1C level, systolic blood pressure (SBP), and other risk factors were assessed.

RESULTS

Of 1,159 patients enrolled, 944 (81.4%) had gradable photographs and 170 (14.7%) had retinopathy. Older age was associated with decreased arteriolar (P = 0.024) and venular (P = 0.002) tortuosity, and female subjects had larger arteriolar branching angle than male subjects (P = 0.03). After adjusting for age and sex, longer diabetes duration was associated with larger arteriolar branching angle (P <or= 0.001) and increased arteriolar optimality deviation (P = 0.018), higher A1C was associated with increased arteriolar tortuosity (>8.5 vs. <or=8.5%, P = 0.008), higher SBP was associated with decreased arteriolar LDR (P = 0.002), and higher total cholesterol levels were associated with increased arteriolar LDR (P = 0.044) and decreased venular optimality deviation (P = 0.044). These associations remained after controlling for A1C, retinal vessel caliber, and retinopathy status and were seen in subjects without retinopathy.

CONCLUSIONS

Key diabetes-related factors affect retinal microvascular geometry in young type 1 diabetes, even in those without evidence of retinopathy. These early retinal alterations may be markers of diabetes microvascular complications.

Cortisol response to general anaesthesia for medical imaging in children

OBJECTIVE

The cortisol response to surgical stress has been frequently studied, and recommendations developed for steroid replacement in adrenally insufficient patients. There are currently no guidelines, however, for adrenal hormone replacement during anaesthesia alone. The objective of this study was to characterize the normal cortisol response to general anaesthesia in the absence of a surgical procedure in children.

DESIGN

Prospective observational study.

PATIENTS

Thirty-seven children (aged 0.5-7 years) without known endocrine disease or cranial neoplasms undergoing outpatient magnetic resonance imaging, under general anaesthesia for investigation of nonacute problems in a tertiary referral paediatric hospital.

MEASUREMENTS

Serum cortisol and salivary cortisol were measured before and after anaesthesia and during recovery.

RESULTS

The mean cortisol level was 303 (± 117) nmol/l at induction, 396 (± 241) nmol/l at emergence from anaesthesia and 584 (± 218) nmol/l during recovery. A stress response (increase in serum cortisol >550 nmol/l) occurred in 23% of children at emergence and in 52% of children at recovery. Eight children (31%) actually demonstrated a decrease in cortisol levels during anaesthesia, without an increase in complications. Mean salivary cortisol levels were 6.5 ± 4.8 nmol/l before induction, 23.5 ± 13.8 nmol/l at emergence from anaesthesia and 26.9 ± 21.6 nmol/l during recovery. A stress response (an increase in salivary cortisol greater than seven-fold) occurred in 26% of children during the study.

CONCLUSIONS

While some children demonstrated a rise in their cortisol levels in response to anaesthesia without surgery, the response was variable and often more pronounced during recovery. There was consistently no classic stress response.

Retinal vascular fractal dimension and risk of early diabetic retinopathy: A prospective study of children and adolescents with type 1 diabetes

OBJECTIVE

To examine the prospective association of retinal vascular fractal dimension with diabetic retinopathy risk in young people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

This was a hospital-based prospective study of 590 patients aged 12-20 years with type 1 diabetes free of retinopathy at baseline. All patients had seven-field retinal photographs taken of both eyes. Incident retinopathy was ascertained from retinal photographs taken at follow-up visits. Fractal dimension was measured from baseline photographs using a computer-based program following a standardized protocol.

RESULTS

Over a mean +/- SD follow-up period of 2.9 +/- 2.0 years, 262 participants developed mild nonproliferative diabetic retinopathy (15.0 per 100 person-years). After adjusting for age, sex, diabetes duration, A1C, and other risk factors, we found no association between retinal vascular fractal dimension and incident retinopathy.

CONCLUSIONS

Retinal vascular fractal dimension was not associated with incident early diabetic retinopathy in this sample of children and adolescents with type 1 diabetes.

Quantitative assessment of early diabetic retinopathy using fractal analysis

OBJECTIVE

Fractal analysis can quantify the geometric complexity of the retinal vascular branching pattern and may therefore offer a new method to quantify early diabetic microvascular damage. In this study, we examined the relationship between retinal fractal dimension and retinopathy in young individuals with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional study of 729 patients with type 1 diabetes (aged 12-20 years) who had seven-field stereoscopic retinal photographs taken of both eyes. From these photographs, retinopathy was graded according to the modified Airlie House classification, and fractal dimension was quantified using a computer-based program following a standardized protocol.

RESULTS

In this study, 137 patients (18.8%) had diabetic retinopathy signs; of these, 105 had mild retinopathy. Median (interquartile range) retinal fractal dimension was 1.46214 (1.45023-1.47217). After adjustment for age, sex, diabetes duration, A1C, blood pressure, and total cholesterol, increasing retinal vascular fractal dimension was significantly associated with increasing odds of retinopathy (odds ratio 3.92 [95% CI 2.02-7.61] for fourth versus first quartile of fractal dimension). In multivariate analysis, each 0.01 increase in retinal vascular fractal dimension was associated with a nearly 40% increased odds of retinopathy (1.37 [1.21-1.56]). This association remained after additional adjustment for retinal vascular caliber.

CONCLUSIONS

Greater retinal fractal dimension, representing increased geometric complexity of the retinal vasculature, is independently associated with early diabetic retinopathy signs in type 1 diabetes. Fractal analysis of fundus photographs may allow quantitative measurement of early diabetic microvascular damage.

Retinal arteriolar dilation predicts retinopathy in adolescents with type 1 diabetes

OBJECTIVE

Alterations in retinal vascular caliber may reflect early subclinical microvascular dysfunction. In this study, we examined the association of retinal vascular caliber to incident retinopathy in young patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

This was a prospective cohort study of 645 initially retinopathy-free type 1 diabetic patients, aged 12-20 years. Participants had seven-field stereoscopic retinal photographs taken of both eyes at baseline and follow-up. Retinal vascular caliber was measured from baseline photographs using a computer-based program following a standardized protocol. Incident retinopathy was graded according to the modified Airlie House classification from follow-up photographs.

RESULTS

Over a median follow-up of 2.5 years, 274 participants developed retinopathy (14.8 per 100 person-years). After adjustments for age, sex, diabetes duration, glycemia, mean arterial blood pressure, BMI, and cholesterol levels, larger retinal arteriolar caliber (fourth versus first quartile) was associated with a more than threefold higher risk of retinopathy (hazard rate ratio 3.44 [95% CI 2.08-5.66]). Each SD increase in retinal arteriolar caliber was associated with a 46% increase in retinopathy risk (1.46 [1.22-1.74]). This association was stronger in female than in male participants. After similar adjustments, retinal venular caliber was not consistently associated with incident retinopathy.

CONCLUSIONS

Retinal arteriolar dilatation predicts retinopathy development in young patients with type 1 diabetes. Our data suggest that arteriolar dysfunction may play a critical role in the pathogenesis of early diabetic retinopathy and that computer-based retinal vascular caliber measurements may provide additional prognostic information regarding risk of diabetes microvascular complications.

Role of blood pressure in development of early retinopathy in adolescents with type 1 diabetes: prospective cohort study

OBJECTIVE

To examine the relation between blood pressure and the development of early retinopathy in adolescents with childhood onset type 1 diabetes.

DESIGN

Prospective cohort study.

SETTING

Diabetes Complications Assessment Service at the Children's Hospital at Westmead, Sydney, Australia.

PARTICIPANTS

1869 patients with type 1 diabetes (54% female) screened for retinopathy with baseline median age 13.4 (interquartile range 12.0-15.2) years, duration 4.9 (3.1-7.0) years, and albumin excretion rate of 4.4 (3.1-6.8) microg/min plus a subgroup of 1093 patients retinopathy-free at baseline and followed for a median 4.1 (2.4-6.6) years.

MAIN OUTCOME MEASURES

Early background retinopathy; blood pressure.

RESULTS

Overall, retinopathy developed in 673 (36%) participants at any time point. In the retinopathy-free group, higher systolic blood pressure (odds ratio 1.01, 95% confidence interval 1.003 to 1.02) and diastolic blood pressure (1.01, 1.002 to 1.03) were predictors of retinopathy, after adjustment for albumin excretion rate (1.27, 1.13 to 1.42), haemoglobin A(1c) (1.08, 1.02 to 1.15), duration of diabetes (1.16, 1.13 to 1.19), age (1.13, 1.08 to 1.17), and height (0.98, 0.97 to 0.99). In a subgroup of 1025 patients with albumin excretion rate below 7.5 microg/min, the cumulative risk of retinopathy at 10 years' duration of diabetes was higher for those with systolic blood pressure on or above the 90th centile compared with those below the 90th centile (58% v 35%, P=0.03). The risk was also higher for patients with diastolic blood pressure on or above the 90th centile compared with those below the 90th centile (57% v 35%, P=0.005).

CONCLUSIONS

Both systolic and diastolic blood pressure are predictors of retinopathy and increase the probability of early retinopathy independently of incipient nephropathy in young patients with type 1 diabetes.

Methylenetetrahydrofolate reductase and methionine synthase reductase gene polymorphisms and protection from microvascular complications in adolescents with type 1 diabetes

Folate status has been associated with endothelial dysfunction in adolescents with type 1 diabetes, and elevated total plasma homoocyst(e)ine (tHcy) is a risk for vascular disease in the non-diabetic population. Polymorphisms in genes involved in folate and homocysteine metabolism are implicated in vascular disease. We aimed to determine whether polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genes are risk factors for early microvascular disease in a large group of adolescents with type 1 diabetes. Four hundred and eighty adolescents were screened annually for retinopathy and microalbuminuria for a median of 4 yr. Molecular analysis for the polymorphisms 677C-->T, 1298A-->C in MTHFR, and 66A-->G in MTRR was performed. The MTRR 66GG genotype reduced the risk for elevated albumin excretion rate (AER) (OR 0.47, CI 0.25, 0.88, p = 0.018) and showed a trend to reduced risk for microalbuminuria (OR 0.27, CI 0.06-1.21, p = 0.09). Survival without elevated AER was increased with the MTRR 66GG genotype (12.4 vs. 9.7 yr, p = 0.04) and with the MTHFR 1298CC genotype (15.2 vs. 10.2 yr, p = 0.007). Conversely, survival without retinopathy was reduced with the MTHFR 677TT and MTRR 66GG combined genotype (6.2 vs. 10.2 yr, p = 0.015). The MTRR 66GG and MTHFR 1298 CC genotypes may confer protection against early nephropathy, possibly because they are associated with lower tHcy. The MTHFR 677 TT was only related to earlier onset retinopathy in combination with MTRR 66GG.

Association between p.Leu54Met polymorphism at the paraoxonase-1 gene and plantar fascia thickness in young subjects with type 1 diabetes

OBJECTIVE

In type 1 diabetes, plantar fascia, a collagen-rich tissue, is susceptible to glycation and oxidation. Paraoxonase-1 (PON1) is an HDL-bound antioxidant enzyme. PON1 polymorphisms have been associated with susceptibility to macro- and microvascular complications. We investigated the relationship between plantar fascia thickness (PFT) and PON1 gene variants, p.Leu54Met, p.Gln192Arg, and c.-107C>T, in type 1 diabetes.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study of 331 adolescents with type 1 diabetes (162 male and 169 female). PFT was assessed by ultrasound, PON1 was assessed by genotyping with PCR and restriction fragment-length polymorphism, and serum PON1 activity was assessed by rates of hydrolysis of paraoxon and phenylacetate.

RESULTS

Median (interquartile range) age was 15.4 (13.5-17.3) years, and diabetes duration was 7.6 (4.9-10.6) years. The distribution of p.Leu54Met genotypes was LL 135 (40.8%), ML 149 (45%), and MM 47 (14.2%). PFT was abnormal (>1.7 mm) in 159 adolescents (48%). In multivariate analysis, predictors of abnormal PFT were ML/LL versus MM p.Leu54Met polymorphism (odds ratio 3.84 [95% CI 1.49-9.82], P = 0.005); BMI (percentile) (1.02 [1.01-1.03], P = 0.007); systolic blood pressure (percentile) (1.01 [1.00-1.02], P = 0.03); and male sex (3.29 [1.98-5.46], P < 0.001).

CONCLUSIONS

Thickening of the plantar aponeurosis occurs predominantly in overweight and male adolescents with type 1 diabetes. The MM genotype at PON1 p.Leu54Met is associated with a reduced risk of abnormal PFT.