Objective. The aim of the study was to estimate the pancreatic beta cell function and insulin resistance indexes in a group of Autosomal Dominant Polycystic Kidney Disease (ADPKD) patients with normal kidney function and no previous diabetes mellitus diagnosis. Methods. A total of 49 adult patients with ADPKD aged 36 ± 11 years, and 50 healthy controls, all of Caucasian origin, were included in the study. Blood glucose, insulin and C-peptide concentrations were measured during an oral glucose tolerance test (OGTT with 75 g glucose) performed according to WHO recommendations in all subjects. Results. The insulin/glucose ratio at the 30th and 120th minute of the OGTT and the insulinogenic index [(insulin at 30 min – insulin at 0 min)/glucose at 30 min] were significantly lower (p = 0.018, p = 0.031 and p = 0.013, respectively) in the ADPKD group. Four other indexes of beta cell function were lower with the borderline statistical significance (p = 0.054–0.076) than in controls. None of the calculated insulin sensitivity indexes differed between the study and control groups. Conclusions. Presence of ADPKD in patients with normal kidney function is associated with impaired beta cell function after an oral glucose load, without a significant decrease in insulin sensitivity.

Background: The aim of this work was to compare the prevalence of the metabolic syndrome (MS) and its components between a group of autosomal-dominant polycystic kidney disease (ADPKD) patients with normal kidney function and no prior diagnosis of diabetes and healthy controls. Methods: Forty-nine patients with ADPKD (age 35.9 ± 11.1 years) with serum creatinine <1.35 mg/dl and 50 healthy controls (36.7 ± 9.2 years) were enrolled for the study. Physical examination, basic laboratory measurements and oral glucose tolerance test were performed in all subjects. Results: In the group of ADPKD patients, when compared to controls, the following values were significantly higher: waist-to-hip ratio (0.84 ± 0.09 vs. 0.81 ± 0.10, p = 0.046), systolic blood pressure (133.9 ± 19.8 vs. 122.2 ± 14.9 mm Hg, p = 0.0023), diastolic blood pressure (92.9 ± 12.4 vs. 82.9 ± 9.3 mm Hg, p < 0.0001), fasting glycemia (91.6 ± 10.5 vs. 84.5 ± 9.2 mg/dl, p = 0.04), and HbA1C (5.41 ± 0.35 vs. 5.28 ± 0.33%, p = 0.06, borderline significance). Adult Treatment Panel III criteria of MS were fulfilled by 14% of patients and 14% of controls, while International Diabetes Federation criteria were fulfilled by 22% of patients and 20% of controls, without any significant difference between the groups. Conclusion: The presence of ADPKD with normal kidney function is associated with components of MS such as hypertension, abdominal obesity and higher fasting glycemia.

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease with a prevalence of 1:400 to 1:1,000 in Caucasians. It is caused by mutations in the PKD1 gene located on chromosome 16p13.3 (in about 85% cases) as well as in the PKD2 gene on chromosome 4q13-23. In the Polish population, the disease is associated with PKD1 mutations in 84% of the ADPKD-affected families. PKD1 and PKD2 genes encode the proteins polycystin-1 (PC1) and polycystin-2 (PC2), respectively. The presence of kidney cysts is a characteristic feature in the ADPKD patients. But in the ADPKD patients, cardiovascular abnormalities, such as hypertension (HT) with higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) values, higher left ventricular mass (LVM), intracranial (ICAN) and extracranial aneurysms, and cardiac valve defects, are significantly more common than in the general population. Summary: According to the literature data, both higher LVM and vascular dysfunction already occur in children and young adults with normal renal function and without HT. Moreover, biventricular diastolic dysfunction, endothelial dysfunction, increased carotid intima-media thickness, and impaired coronary flow velocity reserve are present even in young patients with ADPKD who have normal HT and well-preserved renal function. In patients with ADPKD, hypertension has some specific features; in the youngest age group of children, the prevalence of hypertension is greater if their parents suffer from hypertension; in normotensive young ADPKD-diagnosed individuals, ambulant SBP and DBP values were significantly higher than in age- and gender-matched controls; hypertension appears at least 10 years earlier than spontaneous HT in general population. In adults, HT is often diagnosed before any substantial reduction in the GFR, and a lower nocturnal dip in BP in comparison to hypertensives in the general population. PKD1 and PKD2 gene products (PC1 and PC2 proteins) have been shown to assemble at the plasma membrane and to regulate calcium (Ca2+) entry. A defect in Ca2+ binding mediated by mutations in polycystin proteins is a hypothetical factor contributing to left ventricular mass increase. Altered intracellular Ca2+ handling contributes importantly to impaired contractility associated with heart failure. Impairment of intracellular Ca2+ homeostasis and mitochondrial function has been implicated in the development of LVH. Key Messages: It can be assumed that the cause of LVH in ADPKD patients is the natural course of this disease with developing HT and deteriorating kidney function, which may be influenced by the presence of PKD1- and PKD2-mutated gene products: PC1 and PC2 proteins.

Introduction: The aim of this study was to assess calcium-phosphate metabolism of autosomal dominant polycystic kidney disease (ADPKD) patients with a special consideration to the following serum parameters: calcium (Ca 2+ ), inorganic phosphate (Pi), parathyroid hormone (PTH) and intracellular...

The aim of this study was to compare echocardiographic parameters in patients with autosomal dominant polycystic kidney disease (ADPKD) and in controls with normal kidney function taking into account gender and the presence of hypertension. 47 patients with ADPKD (age 36.3 ± 11.0 years) and 49 healthy controls (36.8 ± 9.2 years) were enrolled. M-mode echocardiography was performed in all subjects. Left ventricular hypertrophy (LVH) was diagnosed when the left ventricular mass index (LVMI) was greater than or equal to 125 g/m2 in males and 110 g/m2 in females. The prevalence of LVH was greater in ADPKD patients than in controls (13% vs. 2%; p=0.05). Among females, ADPKD patients demonstrated greater LVMI (87.9 ± 18.5 vs. 68.8 ± 15 g/m2, p=0.00009) than controls. There was a positive correlation between LVMI and blood pressure in ADPKD females (Rs=0.54, p=0.027 for systole blood pressure-SBP and Rs=0.50, p=0.0053 for diastole blood pressure-DBP) but not in males. Left ventricular mass is increased in ADPKD females with normal renal function. A positive correlation between SBP and DBP and LVMI was found in ADPKD females but not in ADPKD males.