Agata Grzelka

Does serum cystatin C level reflect insulin resistance in patients with type 1 diabetes

OBJECTIVES The aim of study was to evaluate the relationship between serum cystatin C and insulin resistance (IR) in type 1 diabetic patients being the participants of Poznan Prospective Study. DESIGN AND METHODS The study was performed on 71 Caucasian patients (46 men); with type 1 diabetes, who were recruited into the Poznan Prospective Study, at the age of 39±6.1 meanly, and treated with intensive insulin therapy since the onset of the disease. The follow-up period and diabetes duration were 15±1.6 years. Insulin resistance (IR) was assessed by estimated glucose disposal rate (eGDR) calculation with cut-off point 7.5 mg/kg/min. Patients were divided into two groups, according to the presence or absence of IR. RESULTS From among 71 patients, 31 patients (43.7%) presented decreased sensitive to insulin with eGDR below 7.5 mg/kg/min. Patients who had eGDR <7.5 mg/kg/min (insulin resistant), compared with subjects with eGDR >7.5 mg/kg/min (insulin sensitive), had higher level of serum cystatin C [0.59 (IQR:0.44-0.84) vs 0.46 (IQR:0.37-0.55) mg/L, p=0.009]. A significant negative correlation between cystatin C and eGDR was revealed (Rs=-0.39, p=0.001). In regression model cystatin C was related to insulin resistance, adjusted for sex, BMI, eGFR and duration of diabetes [OR 0.03 (0.001-0.56), p=0.01]. CONCLUSIONS Higher level of serum cystatin C is related to decreased insulin sensitivity in patients with type 1 diabetes. This relationship seems to have an important clinical implication.

Higher free triiodothyronine concentration is associated with lower prevalence of microangiopathic complications and better metabolic control in adult euthyroid people with type 1 diabetes

PurposeType 1 diabetes mellitus (T1DM) is a disorder of insulin deficiency but with a wide range of hormones simultaneously disturbed. The study was performed to explore relation of free triiodothyronine (FT3) with metabolic control and occurrence of microangiopathic complications.MethodsA total of 266 adult T1DM participants [56% men; 32 (interquartile range, IQR: 25–39) years and disease duration 13 (IQR: 8–19) years] in euthyroid state with negative history for hypothyroidism were included to the study. Participants were screened for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and FT3. Moreover, microangiopathic complications (retinopathy, diabetic kidney disease, peripheral and autonomic neuropathy), markers of metabolic control such as glycated hemoglobin (HbA1c) were evaluated.ResultsA total of 114 (42.9%) people had diagnosed at least one microangiopathic complication. In multivariable linear regression higher HbA1c was statistically significant independent predictor of lower FT3 (β = −0.25; p < 0.0001) after adjustment for sex, T1DM duration, HbA1c, waist-to-hip ratio (WHR) (R2 = 0.15, p < 0.0001). Higher FT3 was simultaneously a predictor of lower prevalence of microangiopathy in multivariate logistic regression analysis (odds ratio, 0.51; 95% confidence interval, 0.27–0.98; p = 0.04) after an adjustment for: age, hypertension, HbA1c, WHR and total cholesterol (TC).ConclusionsFT3 as tissue active hormone plays a clinically important role in T1DM people. The higher FT3 concentration is related to the lower prevalence of microangiopathy and better metabolic control of the disease in adult euthyroid people with T1DM.

Higher concentrations of osteoprotegerin in type 1 diabetic patients are related to retinopathy: Results from the Poznań Prospective Study

BACKGROUND Osteoprotegerin (OPG) is an arterial calcification marker which has been associated with vascular damage. Elevated OPG concentrations associated with low-grade inflammatory processes are found in diabetic subjects. OBJECTIVES The aim of the study was to assess concentrations of OPG in relation to the presence of diabetic complications in patients with diabetes type 1 (DM 1) participating in the Poznań Prospective Study (PoProStu). MATERIAL AND METHODS The study included 74 patients with DM1 (48 men) with a median age of 39 years (interquartile range [IQR]: 34-43) and a median 15-year history (IQR: 14-16) of diabetes, who were participants in the PoProStu. Serum OPG concentration was measured using the ELISA method, and serum concentration of C-reactive protein was measured with a high sensitivity test (hsCRP). The visceral adipose index (VAI) was used to determine indirect markers of insulin resistance (IR). The prevalence of microangiopathic diabetes complications was assessed. RESULTS Retinopathy was diagnosed in 28 patients (38%), diabetic kidney disease (DKD) in 28 (38%) patients, and neuropathy in 17 (23%) patients. The median OPG level was 43.8 (28.0-74.0) pg/mL. Patients with retinopathy had higher levels of OPG than those without retinopathy: 47.5 (35.0-88.0) vs 35.4 (24.7-69.4) pg/mL (p = 0.04). Positive correlations were observed between OPG concentration and hsCRP (Rs = 0.53; p < 0.001), HbA1c level (Rs = 0.36; p = 0.002), VAI (Rs = 0.23; p = 0.04) and waist circumference (Rs = 0.24; p = 0.04). CONCLUSIONS Higher concentrations of osteoprotegerin in DM1 patients are related to the presence of retinopathy. The study results indicate that OPG might play a role in the pathogenesis of vascular complications in association with hyperglycemia and low-grade inflammatory processes.

Insulin therapy and lipoproteins in patients with type 1 diabetes

Knowledge on HDL cholesterol has been extended, however, there are still unknown facts, especially concerning HDL cholesterol, type 1 diabetes mellitus and insulin therapy. It is known that HDL is responsible for the transport of cholesterol to the liver. It is called the “good cholesterol” due to its advantageous properties. HDL cholesterol reduces cardiovascular risk by its anti-inflammatory, antioxidant, profibrinolytic and antithrombotic effects. The influence of HDL on the incidence of chronic complications of type 1 diabetes has not been yet fully understood. The researchers observed an increase in HDL cholesterol level after initiation of insulin therapy. Significant is the fact that insulin affects lipoprotein metabolism in type 1 diabetes, as it is the treatment of choice in this group of patients.