Hakan Yavuzer

Circulating miR-21 and eNOS in subclinical atherosclerosis in patients with hypertension

Abstract Objectives: The aim of this study is to evaluate the relationship of miR-21, nitric oxide (NOx) and endothelial nitric oxide synthase (eNOS) with subclinical atherosclerosis in carotid arteries by measuring carotid intima media thickness (CIMT) in patients with hypertension and healthy controls. Design and Methods: A total of 28 hypertensive and 28 healthy controls were enrolled. MiR-21 expression was analyzed by quantitative reverse transcription-PCR and NOx, and eNOS levels were measured by ELISA assay. CIMT was evaluated by ultrasonography and CIMT ≥ 0.8 mm was accepted as increased CIMT (iCIMT). Results: C-reactive protein (CRP) level, plasma miR-21 expression level and CIMT were found to be significantly higher in the hypertension group when compared to the control group (p = 0.009, p = 0.002 and p < 0.001, respectively). NOx and eNOS levels were significantly lower in the hypertension group compared to the control group (p < 0.001, both). MiR-21 level was positively correlated with the clinical systolic blood pressure, clinical diastolic blood pressure, CRP and CIMT. MiR-21 was also negatively correlated with NOx and eNOS. Eighteen patients with hypertension had iCIMT. MiR-21 and CRP levels were significantly higher (p < 0.001 and p = 0.001), whereas NOx and eNOS levels were significantly lower in patients with iCIMT (p < 0.001, both). Conclusion: The decreased levels of NOx and eNOS found in this study indicate the co-existence of endothelial dysfunction and hypertension once more. In the absence of microalbuminuria, the increased miR-21 expression in patients with iCIMT made us conclude that this miRNA might be involved in the early stages of atherosclerotic process in hypertensive patients.

Differential Expression of Hypertension-associated Micrornas in the Plasma of Patients With White Coat Hypertension

AbstractWhite coat hypertension (WCH) is a high cardiovascular risk condition, and a fundamental understanding of the cause and pathophysiology of the disorder is still lacking. Recent studies demonstrated that microRNAs (miRNAs) are involved in hypertension; however, the roles of miRNAs in WCH are not known.The expressions of selected 10 miRNAs were investigated independently in plasma samples from 30 hypertension (HT) patients, 30 WCH patients, and 30 normotensive (NT) subjects.MiR-21, miR-122, miR-637, and let-7e expression levels were significantly upregulated in the HT group compared with the NT groups (P = 0.017, P = 0.022, P = 0.048, and P = 0.013, respectively). MiR-122 and miR-637 expressions were also significantly upregulated in the WCH group compared with the NT group (P = 0.048 and P = 0.039, respectively). MiR-296-5p expression level was significantly downregulated in HT patients and upregulated in the WCH patients compared with the NT group (P = 0.049 and P = 0.039, respectively).Additionally, the ambulatory 24-hour and daytime systolic and diastolic blood pressures were negatively correlated with miR-296-5p. MiR-296 and miR-637 had area under the curve (AUC) values of 0.778 and 0.774, respectively, which demonstrates their sufficiency to distinguish WCH from NT individuals. MiR-296 and miR-637 had AUC values of 0.868 and 0.680, respectively, which shows their potential to distinguish WCH from HT individuals.We report for the first time a plasma miRNA profile for WCH patients and demonstrate a novel link between miRNA and WCH. These findings may reveal crucial insights into the development of WCH.

Ischemia‐modified albumin and advanced oxidation protein products as potential biomarkers of protein oxidation in Alzheimer's disease

The aim of the present study was to determine the systemic levels of oxidative stress markers, such as ischemia‐modified albumin (IMA), advanced oxidation protein products (AOPP), ferric reducing antioxidant power (FRAP) and the prooxidant–antioxidant balance (PAB), to clarify protein redox homeostasis in patients with Alzheimers disease, and to compare them with mentally healthy persons of the same age.

The efficacy of donepezil administration on acetylcholinesterase activity and altered redox homeostasis in Alzheimer’s disease

Alzheimers disease (AD) is a serious multifactorial disorder with progressive neurodegenerative outcomes related with impaired redox homeostasis. Inhibition of the enzyme acetylcholinesterase (AChE), as one of the major therapeutic strategies, is considered to be offering only symptomatic relief and moderate disease modifying effect. We intended to investigate the effects of acetylcholinesterase inhibition via donepezil on protein carbonyl (PCO), advanced protein oxidation products (AOPP) and ischemia modified albumin (IMA) as protein oxidation markers and ferric reducing antioxidant power (FRAP), prooxidant-antioxidant balance (PAB), total thiol (T-SH), protein thiol (P-SH) as antioxidant status markers and also kynurenine (KYN), N-formyl kynurenine (N-FKYN) and protein bound dityrosine (DT) levels all in one demonstrating the redox homeostasis in Alzheimer patients also correlated with AChE activity. The AChE activity and PCO, KYN, N-FKYN and DT levels were found to be significantly higher in the AD group than the control group. The FRAP, T-SH and P-SH levels were significantly lower in the AD group than in the control group. The AChE activity was significantly higher both in donepezil treated and untreated groups when compared with the control group. PCO levels were significantly higher in Alzheimers untreated group than the healthy control and donepezil treated groups. AChE activity was positively correlated with PCO, IMA, PAB, KYN and N-FKYN levels and negatively correlated with FRAP, T-SH and P-SH levels in all participants. Our data showed that treatment with donepezil had ameliorating effects on redox homeostasis in Alzheimer patients. AChE inhibition seems to be exhibiting a potent antioxidant role and may inhibit protein oxidation by decreasing AChE activity in AD, thus medicinal natural substances exhibiting the similar mechanism of action with their antioxidant behaviours can be recommended for the emphasis on new drug new drug development. Further clinical and experimental studies are needed to support our current findings and conclusions.

Biomarkers of lipid peroxidation related to hypertension in aging

The aim of this clinical study was to evaluate the influence of aging on the levels of lipid peroxidation (quantified as thiobarbituric acid-reactive substances (TBARS) content), lipid hydroperoxide (LOOH), hexanoyl lysine (HEL), 8-iso-prostaglandin F2α (8-iso-PGF2α) and total antioxidant capacity (TAC), and determine their relationships to the demographic and cardiovascular risk factors in elderly hypertensive (HT) patients. This study consisted of four groups: two elderly groups with 30 HT patients (11 males, 19 females) and 30 normotensive healthy volunteers (15 males, 15 females), and two young groups with 30 HT patients (13 males, 17 females) and 30 normotensive healthy volunteers (12 males, 18 females). In the elderly control group, the TBARS, LOOH, HEL and 8-iso-PGF2α levels, and the carotid intima media thickness (CIMT) were significantly higher than in the young control group. The TBARS, LOOH, HEL and 8-iso-PGF2α levels and the CIMT measurements were significantly higher in the elderly HT group than in the young HT group. In addition, the TAC levels were significantly lower in the elderly and young HT groups than in the elderly and young control groups. The CIMT was significantly positively correlated with TBARS (r=0.40, P<0.001), HEL (r= 0.30, P=0.001), LOOH (r= 0.44, P<0.001) and 8-iso-PGF2α (r= 0.32, P<0.001) in all of the HT groups. It seems that in elderly patients, the LOOH and TBARS are better biomarkers of lipid peroxidation in hypertension in terms of sensitivity. In all of the HT groups, 8-iso-PGF2α had the highest sensitivity. Hypertension is associated with lipid peroxidation due to an impaired oxidant/antioxidant status. Increased lipid peroxidation and decreased antioxidants with aging indicate that peroxidative damage further increases with higher blood pressure and the aging process.

Primary sarcopenia in older people with normal nutrition

ObjectiveThe aim of this study was to investigate the presence of primary sarcopenia in older patients with normal nutrition and to assess the relationships between the primary sarcopenia with anthropometric measurements.Design and methodsIn this prospective clinical cross-sectional study, six-hundred patients who applied to Polyclinic of Geriatrics between dates 2010 and 2011 have been evaluated. The 386 patients who were supposed to have potential secondary sarcopenia were excluded from the study. Age, gender, weight, height, BMI, calf and waist circumference, ongoing medications, additional diseases of the 214 patients included in the study have been surveyed. The sarcopenia criteria of EWSGOP have been applied.ResultsTwo hundred fourteen cases included in the study were composed of 148 female and 66 male subjects. Mean age was 71.8 ± 2.1 years. Sarcopenia was detected in 105 subjects while 109 (51%) were normal. Sixty-four female (61%) and 41 (39%) male subjects were sarcopenic. Normal group included 84 female (77%) and 25 male (23%) subjects. Incidence of sarcopenia was found higher in the female patients (p<0.001). No statistically significant difference was detected between sarcopenic and normal groups with respect to age, height, weight, calf circumference and evaluation tests. Waist circumference was higher in the sarcopenic group than the normal group (p=0.02). When both groups were analyzed for BMI; 53 (51%) of the 105 sarcopenic patients had BMI over 30 kg/m2 while 29 (27%) and 23 (22%) patients had BMI of 25–30 kg/m2 and below 25 kg/m2, respectively. Incidence of sarcopenia was significantly higher in the group with BMI over 30 kg/m2 when compared with the groups with BMI of 25–30 kg/m2 and below 25 kg/m2 (p=0.01).ConclusionSarcopenia that makes older people physically dependent and decreases their quality of life that receive sufficient nutritional support and are also obese should be comprehensively investigated with respect to presence of sarcopenia.

Does plasma phoenixin level associate with cognition? Comparison between subjective memory complaint, mild cognitive impairment, and mild Alzheimer's disease

BACKGROUND Alteration in energy expenditure or metabolism is the most accused risk issue for the onset and for the course of neurodegenerative cognitive disorders. Neuropeptides are suggested to be related with learning and memory. Phoenixin (PNX) is the most recently reported neuropeptide and we aimed to compare the plasma level in people with subjective memory complaints, patients with mild cognitive impairment, and mild Alzheimers disease (AD). METHODS Ninety two participants enrolled in the study. After screening tests, all participants were assessed with a neuropsychological battery for further cognitive evaluations. We used ELISA kit to assay the level of Human PNX. RESULTS Patients with AD were significantly older than people in subjective memory complaint group (p = 0.02). There was no significant difference between groups according to gender (p = 0.435). Mean plasma PNX level was not significantly different between groups (p = 0.279). Mean plasma PNX level in MCI group was positively correlated with BMI (r = 0.402 and p = 0.028), serum HDL level (r = 0.454 and p = 0.012), blood systolic pressure (r = 0.428 and p = 0.018) and negatively correlated with logical memory (r=-0.335 and p=0.031). The mean plasma PNX level was positively correlated with immediate recall in subjective memory complaint group (r = 0.417 and p = 0.034). CONCLUSION This study is the first studying the association of plasma PNX level and cognitive complaints or decline. The knowledge about the role, interaction, and physiological functions of PNX is lacking. Lower plasma PNX level might be important in prodromal stages as MCI and the predictive role of PNX should be investigated in further studies.

The role of protein oxidation and DNA damage in elderly hypertension

IntroductionThis study aimed to evaluate the role of protein oxidation and DNA damage in the elderly hypertensive (HT) patients.Materials and methodsThis study consisted of four groups: two elderly groups with 30 HT patients and 30 normotensive healthy volunteers, and two young groups with 30 HT patients and 30 normotensive healthy volunteers. Plasma total thiol (T-SH), advanced oxidation protein products (AOPPs), protein carbonyl (PCO), ischemia modified albumin (IMA), urine 8-hydroxy-2′-deoxyguanosine (8-OHdG), and prooxidant–antioxidant balance (PAB) levels were measured.ResultsIn the elderly HT group AOPPs, PCO, 8-OHdG, and PAB were significantly higher than the elderly control group. In the young HT group T-SH levels were significantly lower and the other oxidative stress parameters were significantly higher than the young control group. In the elderly control group AOPPs, PCO, IMA, 8-OHdG and PAB were significantly higher than the young control group. T-SH was significantly lower in the elderly control than the young control group. In the elderly HT group, T-SH levels were significantly lower and AOPPs, PCO, IMA, 8-OHdG, and PAB levels were significantly higher than the young HT group.ConclusionProtein and DNA cell damage occurs by oxidation of free radicals throughout life. Our study supports the view that these radicals may be responsible for the development of hypertension with aging process. Urine 8-OHdG levels can be used as a marker for oxidative DNA damage in the elderly hypertensive patients. Finally, our results suggest that oxidative stress may influence both the development and progression of hypertension and aging.

Acromegaly and aging: A comparative cross-sectional study

OBJECTIVE Cognitive and functional geriatric assessment may change in acromegaly. Herein we aimed to determine at which points geriatric assessment of the cases with acromegaly differs from that of general elderly population. DESIGN In this comparative cross-sectional study, a total of 30 cases with acromegaly (controlled n = 14, uncontrolled n = 16) and 30 gender and body-mass index-matched cases without acromegaly (control group, CG) above 60 years old were included. Cognitive functions were evaluated on the basis of the mini-mental state exam (MMSE). Affective status was determined using the geriatric depression scale. Activities of daily living (ADL) were ranked according to the Barthel index while instrumental activities of daily living (IADL) were graded on the basis of the Lawton scale. Nutritional status was evaluated using the mini-nutritional assessment (MNA). Body composition was measured through bioimpedance analysis. Functional mobility was determined using the Timed Up and Go test (TUG) and muscle strength with the handgrip strength test. RESULTS Scores on the MMSE were significantly lower in the elderly cases with acromegaly than in the cases without acromegaly (p < 0.001). Dementia was more frequent in the acromegaly group than in the CG (p = 0.04). Total MNA scores were significantly lower in cases with acromegaly than in the CG (p = 0.006). More subjects in the acromegaly group (33%) were at greater risk of malnutrition than in the CG (3%) (p = 0.003). There was greater moderate functional impairment based on Barthel ADL in the acromegaly group than in the CG (p = 0.04). CONCLUSION Acromegaly may impair cognitive functions, functional mobility and instrumental daily living activities in the geriatric population. With acromegaly, the risk of malnutrition may also increase.

Single-frequency and multi-frequency bioimpedance analysis: What is the difference?

Bioelectrical impedance analysis is a promising method in determining the body compartments in haemodialysis patients. In this study, we aimed to investigate the agreement between two widely used methods: the single‐frequency and multi‐frequency bioelectrical impedance analyses.