Coregulation Analysis of Mechanistic Biomarkers in Autosomal Dominant Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder leading to deterioration of kidney function and end stage kidney disease (ESKD). A number of molecular processes are dysregulated in ADPKD but the exact mechanism of disease progression is not fully understood. We measured protein biomarkers being linked to ADPKD-associated molecular processes via ELISA in urine and serum in a cohort of ADPKD patients as well as age, gender and eGFR matched CKD patients and healthy controls. ANOVA and t-tests were used to determine differences between cohorts. Spearman correlation coefficient analysis was performed to assess coregulation patterns of individual biomarkers and renal function. Urinary epidermal growth factor (EGF) and serum apelin (APLN) levels were significantly downregulated in ADPKD patients. Serum vascular endothelial growth factor alpha (VEGFA) and urinary angiotensinogen (AGT) were significantly upregulated in ADPKD patients as compared with healthy controls. Arginine vasopressin (AVP) was significantly upregulated in ADPKD patients as compared with CKD patients. Serum VEGFA and VIM concentrations were positively correlated and urinary EGF levels were negatively correlated with urinary AGT levels. Urinary EGF and AGT levels were furthermore significantly associated with estimated glomerular filtration rate (eGFR) in ADPKD patients. In summary, altered protein concentrations in body fluids of ADPKD patients were found for the mechanistic markers EGF, APLN, VEGFA, AGT, AVP, and VIM. In particular, the connection between EGF and AGT during progression of ADPKD warrants further investigation.

Intra-individual variability of eGFR trajectories in early diabetic kidney disease and lack of performance of prognostic biomarkers.

Studies reporting on biomarkers aiming to predict adverse renal outcomes in patients with type 2 diabetes and kidney disease (DKD) conventionally define a surrogate endpoint either as a percentage of decrease of eGFR (e.g. ≥ 30%) or an absolute decline (e.g. ≥ 5 ml/min/year). The application of those study results in clinical practise however relies on the assumption of a linear and intra-individually stable progression of DKD. We studied 860 patients of the PROVALID study and 178 of an independent population with a relatively preserved eGFR at baseline and at least 5 years of follow up. Individuals with a detrimental prognosis were identified using various thresholds of a percentage or absolute decline of eGFR after each year of follow up. Next, we determined how many of the patients met the same criteria at other points in time. Interindividual eGFR decline was highly variable but in addition intra-individual eGFR trajectories also were frequently non-linear. For example, of all subjects reaching an endpoint defined as a decrease of eGFR by ≥ 30% between baseline and 3 years of follow up, only 60.3 and 45.2% lost at least the same amount between baseline and year 4 or 5. The results were similar when only patients on stable medication or subpopulations based on baseline eGFR or albuminuria status were analyzed or an eGFR decline of ≥ 5 ml/min/1.73m2/year was used. Identification of reliable biomarkers predicting adverse prognosis is a strong clinical need given the large interindividual variability of DKD progression. However, it is conceptually challenging in early DKD because of non-linear intra-individual eGFR trajectories. As a result, the performance of a prognostic biomarker may be accurate after a specific time of follow-up in a single population only.

Will the COVID-19 pandemic slow down in the Northern hemisphere by the onset of summer? An epidemiological hypothesis.

The COVID-19 pandemic has affected most countries of the world. As corona viruses are highly prevalent in the cold season, the question remains whether or not the pandemic will improve with increasing temperatures in the Northern hemisphere. We use data from a primary care registry of almost 15,000 patients over 20 years to retrieve information on viral respiratory infection outbreaks. Our analysis suggests that the severity of the pandemic will be softened by the seasonal change to summer.

The Effects of 3 Weeks of Uphill and Downhill Walking on Blood Lipids and Glucose Metabolism in Pre-Diabetic Men: A Pilot Study.

The prevention of type 2 diabetes in persons at risk for diabetes is of utmost importance. Physical activity in general and even exercises at moderate intensities such as walking significantly reduce the risk of the development of type 2 diabetes. However, it is still a matter of debate whether lipids and glucose metabolism are differently affected by regular concentric (e.g., uphill walking) and eccentric (e.g., downhill walking) endurance exercise. The aim of this study was to investigate the effects of short-term (3 weeks) uphill and downhill walking on glucose metabolism and blood lipids in pre-diabetic middle-aged men in a real world setting. The study was designed as an investigator-initiated 2 group random selection pre-test post-test trial. Sixteen pre-diabetic men (age: 56.9 ± 5.1 years; BMI: 28.1 ± 2.3 kg·m-2) performed 9 uphill (n = 8) or 9 downhill (n = 8) walking sessions within 3 weeks. The primary outcomes were the markers of glucose metabolism and blood lipids measured before and after the training period. After uphill walking glucose tolerance (area under the curve of the oral glucose tolerance test: -43.25 ± 53.12 mg·dl-1; p = 0.05; effect size: 0.81), triglycerides (-48.75 ± 54.49 mg·dl-1; p = 0.036; effect size: 0.89), HDL-C (+7.86 ± 9.54 mg·dl-1; p = 0.05; effect size: 0.82) and total cholesterol/HDL-C ratio (-0.58 ± 0.41; p = 0.012; effect size: 1.39) had significantly improved. No significant metabolic adaptations were found after downhill walking. However, when adjusted for estimated energy expenditure, uphill and downhill walking had equal effects on almost all metabolic parameters. Moreover, the magnitude of the baseline impairments of glucose tolerance was significantly related to the extent of change in both groups. Depending on the fitness level and individual preferences both types of exercise may be useful for the prevention of type 2 diabetes and disorders in lipid metabolism.

Fat-free mass and fasting glucose values in patients with and without statin therapy assigned to age groups between <60 and >75 years.

OBJECTIVE: The aging-associated changes in body composition result in an increased cardiometabolic risk. A tremendous reduction of cardiovascular morbidity and mortality can be obtained by statin therapy. Statins are well tolerated, with myopathy as the most serious negative side effect. Some recently published studies indicate that the incidence of type 2 diabetes might be increased during intensified statin therapy. The aim of our study was to investigate whether statin therapy has an influence on the aging-associated changes in fat-free mass (FFM). METHODS: A total of 3,280 persons attending a medical outdoor center between January 2005 and July 2011 were assigned to 3 age groups from <60 to >75 years. Clinical data, body mass index (BMI), and body composition were evaluated in the different age groups in patients with and without statin therapy. To analyze the impact of statin use on FFM, we regressed a patient's FFM on an interaction term between statin use and age and other control variables. RESULTS: Aging was associated with a decrease in BMI and FFM, while fat mass continuously increased up to the age of >75 years. This was paralleled by a continuous increase in fasting glucose levels in patients with and without statin therapy. The loss of FFM between the age group <60 years and >75 years was more pronounced in statin-treated patients (10.88%) than in non-statin users (8.47%). Creatine phosphokinase values revealed a decrease of 7.77 U/l between the age groups <60 and >75 years in non-statin users and of 14.75 U/l in statin users. Statistical analysis indicated that the effect of statin therapy on FFM is more pronounced in younger than in older patients. CONCLUSIONS: Patients under statin therapy seem to be more vulnerable to the aging-associated lowering of FFM. Diagnostic procedures and interventions to prevent a loss of muscle mass might be of particular advantage in elderly patients under statin therapy.

High cardiorespiratory fitness is more beneficial in pre-diabetic men than women.

OBJECTIVES: To investigate gender-specific relationships between cardiorespiratory fitness and factors that predict the development of diabetes and to identify the risk factors that predict fasting plasma glucose and 2-hour plasma glucose levels. INTRODUCTION: Different risk factors (e.g., low cardiorespiratory fitness) may cause elevated plasma glucose levels in men compared to women. Therefore, gender-specific analyses are needed. METHODS: Cardiorespiratory fitness (maximal power output achieved during a standard cycle ergometry test), resting blood pressure, total serum cholesterol, high-density lipoprotein cholesterol and triglyceride levels were measured in 32 pre-diabetic men (mean age: 57.2 ± 6.8 years; mean body mass index (BMI): 28.5 ± 3.0 kg/m²) and 40 pre-diabetic women (mean age: 55.0 ± 7.3 years, mean BMI: 30.4 ± 5.7 kg/m²). A stepwise regression with backward variable selection was performed to construct models that predict 2-hour and fasting plasma glucose levels. RESULTS: Maximal power output was inversely related to the 2-hour plasma glucose level in the entire group (r= -0.237, p<0.05), but this relationship was significant only for males (r= -0.404, p<0.05). No significant correlation was found between female gender and cardiorespiratory fitness. Age and cardiorespiratory fitness were significant predictors of 2-hour plasma glucose levels in men. High-density lipoprotein cholesterol was predictive of 2-hour plasma glucose levels in women. Triglycerides in women and BMI in men were the only predictors of fasting plasma glucose levels. CONCLUSIONS: These findings may have consequences for the development of gender-specific diabetes prevention programs. Whereas increasing cardiorespiratory fitness should be a key goal for men, improving the lipid profile seems to be more beneficial for women. However, the present results do not negate the positive effects of increasing cardiorespiratory fitness in women.

High cardiorespiratory fitness is more beneficial in pre-diabetic men than women

OBJECTIVES: To investigate gender-specific relationships between cardiorespiratory fitness and factors that predict the development of diabetes and to identify the risk factors that predict fasting plasma glucose and 2-hour plasma glucose levels. INTRODUCTION: Different risk factors (e.g., low cardiorespiratory fitness) may cause elevated plasma glucose levels in men compared to women. Therefore, gender-specific analyses are needed. METHODS: Cardiorespiratory fitness (maximal power output achieved during a standard cycle ergometry test), resting blood pressure, total serum cholesterol, high-density lipoprotein cholesterol and triglyceride levels were measured in 32 pre-diabetic men (mean age: 57.2 + 6.8 years; mean body mass index (BMI): 28.5 + 3.0 kg/m²) and 40 pre-diabetic women (mean age: 55.0 + 7.3 years, mean BMI: 30.4+5.7 kg/m²). A stepwise regression with backward variable selection was performed to construct models that predict 2-hour and fasting plasma glucose levels. RESULTS: Maximal power output was inversely related to the 2-hour plasma glucose level in the entire group (r= -0.237, p<0.05), but this relationship was significant only for males (r= -0.404, p<0.05). No significant correlation was found between female gender and cardiorespiratory fitness. Age and cardiorespiratory fitness were significant predictors of 2-hour plasma glucose levels in men. High-density lipoprotein cholesterol was predictive of 2-hour plasma glucose levels in women. Triglycerides in women and BMI in men were the only predictors of fasting plasma glucose levels. CONCLUSIONS: These findings may have consequences for the development of gender-specific diabetes prevention programs. Whereas increasing cardiorespiratory fitness should be a key goal for men, improving the lipid profile seems to be more beneficial for women. However, the present results do not negate the positive effects of increasing cardiorespiratory fitness in women.

Breath isoprene--aspects of normal physiology related to age, gender and cholesterol profile as determined in a proton transfer reaction mass spectrometry study.

BACKGROUND: This study was performed to clarify variations in breath isoprene concentrations with age, gender, body mass index (BMI) and total serum cholesterol. Our cohort consisted of 205 adult volunteers of different smoking background without health complaints. Total cholesterol in blood serum was measured in 79 of these volunteers. METHODS: Mixed expiratory exhaled breath was sampled using Tedlar bags. Concentrations of isoprene were then determined using proton transfer reaction-mass spectrometry. RESULTS: Isoprene concentrations ranged from 5.8 to 274.9 ppb, with an overall geometric mean (GM) of 99.3 ppb. There was no statistically significant difference in mean isoprene in breath between males and females (GM 105.4 and 95.5 ppb, respectively). Ageing led to a decrease in concentration in men, with an estimated slope of the regression line for log-transformed isoprene concentrations of -0.0049, but did not influence isoprene levels in women. We did not observe any significant correlation between isoprene breath content and cholesterol level in blood, even after adjusting for the possible influence of age. Similarly, no correlation was found between isoprene levels and BMI. CONCLUSIONS: Isoprene concentrations in exhaled breath showed gender-specific correlations with respect to age. Further investigations are necessary to clarify the relation between isoprene concentrations in exhaled breath and cholesterol levels and synthesis rates in blood.

Compounds enhanced in a mass spectrometric profile of smokers' exhaled breath versus non-smokers as determined in a pilot study using PTR-MS.

A pilot study has been carried out to define typical characteristics of the trace gas compounds in exhaled breath of non-smokers and smokers to assist interpretation of breath analysis data from patients who smoke with respiratory diseases and lung cancer. Exhaled breath was analyzed using proton transfer reaction-mass spectrometry (PTR-MS) for 370 volunteers (81 smokers, 210 non-smokers, 79 ex-smokers). Volatile organic compounds corresponding to product ions at seven mass-to-charge ratios (m/z 28, 42, 69, 79, 93, 97, 123) in the PTR-MS spectra differentiated between smokers and non-smokers. The Youden index (= maximum of sensitivity + specificity - 1, YI) as a measure for differentiation between smokers and non-smokers was YI = 0.43 for ions at the m/z values 28 (tentatively identified as HCN), YI = 0.75 for m/z = 42 (tentatively identified as acetonitrile) and YI = 0.53 for m/z = 79 (tentatively identified as benzene). No statistically significant difference between smokers and non-smokers was observed for the product ions at m/z = 31 and 33 (compounds tentatively identified as formaldehyde and methanol). When interpreting the exhaled breath of lung cancer or COPD patients, who often smoke, compounds appearing at the above-mentioned seven mass-to-charge ratios should be considered with appropriate care to avoid misdiagnosis. Validation studies in larger numbers of patients with more precise delineation of their smoking behavior and using additional analytical techniques such as GC/MS and SIFT-MS should be carried out.

Evaluation of a new insulinotropic agent by using an innovative technology: efficacy and safety of nateglinide determined by continuous glucose monitoring.

Nateglinide, a new insulinotropic agent, specifically targets prandial glycemic excursions. Recently, innovative technologies have become available that provide the possibility to measure 72-h blood glucose values continuously. The aim of this study was to evaluate the effects of nateglinide on 24-h blood glucose profiles in diabetic patients. Eighteen patients with type 2 diabetes mellitus--seven on diet only and 11 on metformin monotherapy--participated in the study. Mean age was 60 years, mean diabetes' duration was 7.4 years, and mean hemoglobin A1c was 8.4%. They underwent a 72-h glucose monitoring using a continuous glucose monitoring system (CGMS, Medtronic MiniMed, Northridge, CA) under their usual diabetes therapy and a standardized breakfast. After this period, therapy with nateglinide, 120 mg three times a day before meals, was initiated. Three days later patients again underwent 72-h glucose monitoring. Mean blood glucose values and mean fasting blood glucose values decreased significantly, from 172 mg/dL before to 131 mg/dL (P< 0.0004) and from 172 mg/dL before to 126 mg/dL (P< 0.0005), respectively, with nateglinide therapy. Postprandial hyperglycemia, expressed as mean blood glucose over a time period of 2 h after a meal, declined significantly after all three daily meals. The number of blood glucose values above 140 mg/dL decreased from 207 without to 98 during nateglinide therapy. Nateglinide was not associated with hypoglycemia or other adverse events. We found in this study, using CGMS, that nateglinide has a glucose-lowering potency that not only affects postprandial hyperglycemia, but also overnight and fasting blood glucose values.

Treatment of severe cancer pain by low-dose continuous subcutaneous morphine.

In a prospective and intraindividually controlled trial, we have compared the efficacy and safety of a continuous subcutaneous morphine infusion with conventional intermittent oral or subcutaneous morphine application. Twenty-eight in-patients with cancer pain received a short-term infusion lasting 2-42 days, and 8 out-patients underwent long-term infusion from 49 to 197 days during the terminal stage of their disease. Continuous subcutaneous morphine infusion significantly (P less than 0.001) improved both pain and quality of life when compared to conventional morphine application. With continuous infusion, 5-48 mg (median 19 mg) of morphine was required daily, significantly (P less than 0.001) less than the 10-90 mg (median 50 mg) necessary with conventional use. As a result of lower dosage, side effects under continuous infusion were infrequent and mild. Constipation occurred in 3 of the 36 patients and was always controlled by the addition of laxatives; no nausea, sedation or respiratory depression were observed. Signs of tolerance developed in 2 patients on long-term infusion, but the use of continuous subcutaneous methadone for 2 weeks reversed the tolerance. The study presented indicates that low-dose continuous subcutaneous morphine provides a valuable treatment modality for severe terminal cancer pain exhibiting a high degree of both efficacy and safety.