Biochemical and clinical markers of endothelial dysfunction do not outweigh traditional risk factors for the presence of diabetic retinopathy in patients with type 1 diabetes.

BACKGROUND: This study aimed to evaluate whether soluble vascular cytoadhesive molecule-1 (sVCAM-1), intracellular cytoadhesive molecule-1 (sICAM-1), and endothelial function as assessed by EndoPat outweighed traditional risk factors for the presence of diabetic retinopathy (DR) in patients with type 1 diabetes (T1D). METHODS: Patients aged ≥ 12 years completed a clinical-epidemiological questionnaire. Fasting venous blood samples were obtained (lipid profile, glycemic control, and C-reactive protein levels). Vascular reactivity was assessed via peripheral arterial tonometry performed by supplying the reactive hyperemia index (RHI) through the EndoPAT device. sVCAM-1 and sICAM-1 levels were measured using multiplex assays. RESULTS: Data were obtained from 187 patients (51.3% female), aged 32 ± 13 years with a disease duration of 14 (6-15) years and mean hemoglobin A1c (HbA1c) of 9.1% ± 2.1%. After adjustments were made, age, HbA1c, arterial blood pressure, and use of drugs that could interfere with endothelial function were found to be associated with DR. No association was noted with sVCAM-1 and sICAM-1 levels and RHI. CONCLUSIONS: In our sample, sVCAM-1, sICAM and EndoPAT did not outweigh the traditional DR risk factors, such as age, high HbA1c, arterial blood pressure, and use of drugs that could interfere with endothelial function and are significantly associated with DR. Further prospective studies should evaluate if markers of endothelial dysfunction could predict diabetes-related micro and macrovascular complications in T1D.

Assessment of microvascular endothelial function in type 1 diabetes using laser speckle contrast imaging.

OBJECTIVE: To test whether laser speckle contrast imaging (LSCI) coupled with physiological post-occlusive reactive hyperemia (PORH) and pharmacological iontophoresis of acetylcholine (ACh) as local vasodilator stimuli could distinguish between cutaneous microvascular responses of Type 1 Diabetes (T1DM)'s patients with endothelial dysfunction and that of healthy controls. METHODS: Patients with T1DM aged ≥12years completed a clinical-epidemiological questionnaire. Data detailing patients' such as daily insulin dose, duration of diabetes, and use of pharmaceuticals such as antihypertensive drugs and statins that could interfere with endothelial function were obtained. Vascular reactivity was assessed in the forearm by LSCI and PORH at baseline and during iontophoresis of ACh using increasing anodic currents of 30, 60, 90, 120, 150 and 180µA in 10second intervals. RESULTS: This study included 50 patients with T1DM and 30 control subjects. The mean resting flux did not differ between patients and control subjects. T1DM patients exhibited endothelial dysfunction upon challenge with physiological or pharmacological stimuli. The microvascular response to both ACh and PORH (i.e., maximum response at peak and amplitude) were significantly reduced in patients with diabetes compared with control subjects (p<0.001). CONCLUSION: We demonstrated that endothelium-dependent skin microvascular vasodilator responses are significantly impaired in patients with T1DM compared to healthy subjects investigated using LSCI coupled with ACh iontophoresis and PORH. Additionally, we find that LSCI is a promising methodology for studying physiological vascular reactivity in T1DM.

Prevalence of thyroid dysfunction in patients with diabetes mellitus.

BACKGROUND: Diabetes mellitus (DM) and thyroid dysfunction (TD) are the two most common endocrine disorders in clinical practice. The unrecognized TD may adversely affect the metabolic control and add more risk to an already predisposing scenario for cardiovascular diseases. The objective of this study was to investigate the prevalence of TD in patients with type 1 and type 2 diabetes mellitus (T1DM and T2DM). METHODS: This is an observational cross-sectional study. Three hundred eighty-six (386) patients with T1DM or T2DM that regularly attended the outpatient clinic of the Diabetes unit, Hospital Universitário Pedro Ernesto, participated in the study. All patients underwent a clinical and laboratory evaluation. Thyroid dysfunction was classified as clinical hypothyroidism (C-Hypo) if TSH > 4.20 µUI/mL and FT4 < 0.93 ng/dL; Subclinical hypothyroidism (SC-Hypo) if TSH > 4.20 µUI/ml and FT4 ranged from 0.93 to 1.7 ng/dL; Subclinical hyperthyroidism (SC-Hyper) if TSH < 0.27 µUI/ml and FT4 in the normal range (0.93 and 1.7 ng/dL) and Clinical hyperthyroidism (C-Hyper) if TSH < 0.27 µUI/ml and FT4 > 1.7 µUI/mL. Autoimmunity were diagnosed when anti-TPO levels were greater than 34 IU/mL. The positive autoimmunity was not considered as a criterion of thyroid dysfunction. RESULTS: The prevalence of TD in all diabetic patients was 14,7%. In patients who had not or denied prior TD the frequency of TD was 13%. The most frequently TD was subclinical hypothyroidism, in 13% of patients with T1DM and in 12% of patients with T2DM. The prevalence of anti-TPO antibodies was 10.8%. Forty-four (11.2%) new cases of TD were diagnosed during the clinical evaluation. The forty-nine patients with prior TD, 50% with T1DM and 76% with T2DM were with normal TSH levels. CONCLUSIONS: We conclude that screening for thyroid disease among patients with diabetes mellitus should be routinely performed considering the prevalence of new cases diagnosed and the possible aggravation the classical risk factors such as hypertension and dyslipidemia, arising from an undiagnosed thyroid dysfunction.