Normoalbuminuric type 1 diabetic patients with retinopathy have an impaired tubular response to desmopressin: its relationship with plasma endothelin-1

Oral glucose tolerance response curve predicts disposition index but not other cardiometabolic risk factors in healthy adolescents

OBJECTIVES

In obese adults the shape of the glucose response curve during an oral glucose tolerance test (OGTT) predicts future type 2 diabetes. Patients with an incessant increase or monophasic curves have increased risk compared to those with biphasic curves. Since type 2 diabetes is associated with increased cardiometabolic risk, we studied whether differences in OGTT response curve are associated with differences in cardiometabolic risk factors in healthy adolescents across a wide body mass index (BMI) range.

METHODS

Sixty-nine (33F/36M), white adolescents (age: 15.2 ± 1.7 years; BMI: 21.5 ± 4.7 kg/m²; mean ± SD) were studied. Risk factors measured included percent body fat, blood pressure, lipids, augmentation index, reactive hyperemia, endothelin 1, plasminogen activator 1, inflammatory markers (interleukin 6, c-reactive protein), insulin secretion, insulin sensitivity (Matusda index), and disposition index (DI).

RESULTS

Thirty-two subjects had biphasic responses; 35 subjects had monophasic responses and two females had incessant increases. Sex did not affect the frequency of responses. Glucose area under the curve during OGTT was greater in those with a mono vs. biphasic curves (p=0.01). Disposition index was markedly lower in subjects with a monophasic curve than in those with a biphasic curve (3.6 [2.3-5.0] vs. 5.8 [3.8-7.6], median [25th, 75th%] p=0.003). Triglyceride to high-density lipoprotein cholesterol (HDL) ratio was higher in subjects with a monophasic curve (p=0.046).

CONCLUSIONS

The decreased disposition index indicates that in healthy adolescents a monophasic response to OGTT is due to decreased insulin secretion relative to the degree of insulin resistance present. This was not associated with differences in most other cardiometabolic risk markers.

TRIAL REGISTRATION

Clinical Trials.gov, NCT02821104.

Relationships of complement components C3 and C4 and their genetics to cardiometabolic risk in healthy, non-Hispanic white adolescents

BACKGROUND

Complement promotes inflammatory and immune responses and may affect cardiometabolic risk. This study was designed to investigate the effect of complement components C3 and C4 on cardiometabolic risk in healthy non-Hispanic white adolescents.

METHODS

Body mass index (BMI), BMI percentile, waist circumference, and percent body fat were assessed in 75 adolescents. Arterial stiffness was assessed using arterial tomography and endothelial function using reactive hyperemia. Fasting lipids, inflammatory markers, and complement levels were measured and oral glucose tolerance test was performed. A single C3 polymorphism and C4 gene copy number variations were assessed.

RESULTS

C3 plasma levels increased with measures of obesity. Endothelial function worsened with increased C3 and C4 levels. Triglycerides and low-density lipoprotein increased and high-density lipoprotein (HDL) and insulin sensitivity decreased with increasing C3 levels, but the relationships were lost when body habitus was included in the model. C4 negatively related to HDL and positively to inflammatory markers. Subjects with at least one C3F allele had increased BMI and fat mass index. HDL was significantly related to C4L, C4S, C4A, and C4B gene copy number variation.

CONCLUSIONS

C3 levels increase with increasing body mass and increased C4 levels and copy number are associated with increased cardiometabolic risk in healthy adolescents.

Increased body fat and reduced insulin sensitivity are associated with impaired endothelial function and subendocardial viability in healthy, non-Hispanic white adolescents

BACKGROUND

Cardiovascular disease has its origins in adolescents. Endothelial dysfunction, arterial stiffness, and decreased endocardial oxygen supply: demand ratios are early functional markers of cardiovascular risk. The goal of this study was to determine the relationships of these markers to physical, inflammatory, and metabolic markers in healthy non-Hispanic, white adolescents.

METHODS

Thirty-four of the 75 subjects were female. Mean age was 15.0 ± 1.7 years and mean body mass index (BMI) was 22.0 ± 5.8 kg/m² (mean ± SD). Reactive hyperemia was measured using venous occlusion plethysmography. Arterial tonometry was used to measure the augmentation index (AIx₇₅ ) and the Buckberg subendocardial viability ratio. Blood samples were taken to measure inflammatory and lipid markers and oral glucose tolerance test was used to assess insulin sensitivity.

RESULTS

Reactive hyperemia decreased as body mass and fat mass increased. It also decreased with increasing neutrophil count. The Buckberg index was higher in males and was positively related to insulin sensitivity even when accounting for age, sex, and resting heart rate. AIx₇₅ was not related to any of the other variables.

CONCLUSIONS

These results demonstrate that increased fat mass and decreased insulin sensitivity are related to poorer vascular function and cardiac risk in adolescents before the development of actual cardiovascular disease.

Microvascular Complications and Prevalence of Nocturia in Japanese Patients With Type 2 Diabetes Mellitus: The Dogo Study

OBJECTIVE

To evaluate the association between microvascular complications and nocturia among Japanese patients with type 2 diabetes mellitus.

METHODS

Study subjects were 731 Japanese patients with type 2 diabetes mellitus. A self-administered questionnaire was used to collect information on the variables under study. Study subjects were considered to have nocturia if they answered "once or more" to the question: "How many times do you typically wake up to urinate from sleeping at night until waking in the morning?" Diabetic neuropathy was diagnosed if the patients showed two or more of the following three characteristics: neuropathic symptoms, the absence of the Achilles reflex, or abnormal vibration perception. Diabetic nephropathy was defined as positive when the estimated glomerular filtration rate was <30 mL/min/1.73 m(2) and/or the urine albumin-to-creatinine ratio was ≥34 mg/mmol creatinine. Several ophthalmology specialists were responsible for evaluating diabetic retinopathy. Adjustment was made for sex, age, body mass index, duration of diabetes mellitus, current smoking, current drinking, hypertension, stroke, ischemic heart disease, and glycated hemoglobin.

RESULTS

The prevalence of nocturia was 80.4%. Diabetic retinopathy was independently positively associated with nocturia (adjusted odds ratio 2.39 [95% confidence interval: 1.08-6.11]). In contrast, diabetic nephropathy or diabetic neuropathy was not associated with nocturia.

CONCLUSION

In Japanese patients with type 2 diabetes mellitus, only diabetic retinopathy was independently positively associated with nocturia.