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Biomedical subjects

Thomas Haak

Publications and source records attributed to Thomas Haak.

8 recordsLinked to original sources
PubMed2006

Effect of MTHFR C677T genotype on survival in type 2 diabetes patients with end-stage diabetic nephropathy.

BACKGROUND: The MTHFR C677T single nucleotide polymorphism TT genotype is associated with increased levels of plasma homocysteine and possibly an effect on cardiovascular mortality. We evaluated the effect of C677T genotype on mortality in a large end-stage renal disease (ESRD) cohort. METHODS: C677T genotype was determined in 439 Caucasians with end-stage diabetic nephropathy (DNP) (cases) recruited from 30 dialysis centres in Southern Germany. A total of 482 type 2 diabetes patients without DNP (no microalbuminuria) at inclusion served as a genotype control collective. Patients were prospectively followed for 4 years. Primary endpoint was all-cause mortality. RESULTS: In contrast to controls, the genotype distribution in cases was not in Hardy-Weinberg equilibrium (HWE, P = 0.003), due to a less than expected number of patients with the TT genotype. The requirements of HWE were met in cases with < 2 years dialysis therapy prior to study inclusion (n = 219). TT genotype was associated with a decreased body mass index (P = 0.002) and long diabetes duration in dialysis patients (P = 0.03). However, TT genotype was not associated with an increased risk of all-cause or cardiac mortality in the total dialysis collective or the subgroup. Also, we observed no association of MTHFR genotype with cardiovascular morbidity in cases or controls (P > 0.05), or with an increased rate of progression to novel microalbuminuria. CONCLUSION: MTHFR 677TT genotype was significantly underrepresented in patients with ESRD in our study, but was not associated with premature mortality in these patients. We found no evidence for survival bias due to C677T genotype in the ESRD cohort, or bias due to genetically determined accelerated progression to novel microalbuminuria in the controls. However, we cannot exclude that the TT genotype protects from progression from microalbuminuria to more advanced stages of DNP, or that TT genotype is associated with premature mortality before a patient progresses to ESRD.

Cohort Studies↗
PubMed2006

Evaluation of a self-management-based patient education program for the treatment and prevention of hypoglycemia-related problems in type 1 diabetes.

OBJECTIVE: Aim of this study was to investigate the effectiveness of a patient education program for the treatment of hypoglycemia-associated problems in type 1 diabetic inpatients. METHODS: In this observational controlled pre-post study, the intervention group (IG; N = 105) participated in the new program, controls (control group CG; N = 102) received conventional patient education on hypoglycemia. RESULTS: Follow-up data (mean follow-up: 6.63 months) were obtained from 177 patients (85.6%). Though severe hypoglycemia also decreased in CG to some degree, the decrease in IG was higher than in CG, but fails to reach significance between groups. Hypoglycemia awareness remained constant in IG, whereas some deterioration was observed in CG (p = 0.06). Prevalence of hypoglycemia-related problems decreased in IG, whereas in CG it remained constant. No differential effects with regard to psychological well being, fear of hypoglycemia and late complications, and control beliefs were observed. CONCLUSION: The results suggest that the new intervention program is an effective treatment. The effectiveness should be confirmed, however, in a randomized controlled trial, also incorporating outpatient settings. PRACTICE IMPLICATIONS: A self-management intervention targeting the patients' health beliefs and attitudes towards hypoglycemia and their diabetes self-management, rather than knowledge-centered patient education, can help to ameliorate or even prevent hypoglycemia-associated problems.

Adult↗
PubMed2005

Vascular endothelial growth factor and its soluble receptor, Flt-1, are not correlated to erythropoietin in diabetics with normal or reduced renal function.

BACKGROUND AND AIMS: Recombinant erythropoietin upregulates the expression of the vascular endothelial growth factor (VEGF) receptors, Flt-1 (VEGFR-1) and KDR/Flk-1 (VEGFR-2), in endothelial cells. The integrity of the VEGF system seems to be crucial for the regulation of endothelial permeability and thus for the avoidance of renal protein leakage. As albuminuria/proteinuria is a hallmark of diabetic nephropathy, we examined cross-sectionally in 35 type 1 and 37 type 2 diabetic patients with various degrees of renal dysfunction and albuminuria whether there was an interrelationship between intrinsic erythropoietin (EPO) and VEGF/Flt-1. METHODS AND RESULTS: In patients with plasma creatinine values < or =1.5 (n = 53) or >1.5 mg/dL (n = 19), the mean serum EPO was 5.6 +/- 4.4 and 10.2 +/- 7.0 mU/mL (P = 0.02), respectively. In the two groups, urinary and serum VEGF(165) concentrations were similarly distributed (mean 94.3 +/- 91.8 vs 108 +/- 72.2 ng/L and 91.7 +/- 76.8 vs 91.9 +/- 74.9 ng/L, respectively; both P = NS). The mean urinary Flt-1 for the two groups amounted to 0.14 +/- 0.35 and 0.51 +/- 0.93 ng/mL (P = 0.045), respectively. No correlation between VEGF or Flt-1 and EPO was apparent. CONCLUSION: Our data suggest that in vivo EPO does not affect the functionality and/or production of components of the VEGF/Flt-1 system in diabetics with normal or reduced renal function.

Adult↗
PubMed2003

Vascular endothelial growth factor in diabetic nephropathy.

BACKGROUND: Vascular endothelial growth factor (VEGF) increases endothelial permeability. VEGF is produced in podocytes and functional receptors are located on endothelial glomerular cells. The aim of the current study in diabetic patients with normal renal function to various degrees of proteinuric nephropathy was therefore to unravel a possible role of the most important isoform VEGF(165) for albuminuria and to investigate the impact of therapy with an inhibitor of the renin-angiotensin system on VEGF(165) secretion. SUBJECTS AND METHODS: A cross-sectional study in 72 patients (41 female, 31 male) with long-standing type 1 (n = 35, mean age 43.3 years, range 22-67) or type 2 (n = 37, mean age 66 years, range 53-83) diabetes mellitus was performed; in 19 patients the serum creatinine value was >1.5 mg/dl. Twenty-six healthy volunteers (17 female, 9 male, mean age 34.8 years, range 19-58) with normal renal function served as controls. Serum and urinary VEGF(165) was measured by ELISA. Urinary albumin was measured nephelometrically. Mann Whitney U tests were used for comparisons. RESULTS: In type 1 and type 2 diabetics mean urinary VEGF(165) concentration amounted to 112 +/- 88 (mean +/- SD) and 88 +/- 85 ng/l, respectively, compared to 101 +/- 60 ng/l in the normal volunteers (NS vs. diabetics). The respective mean urinary albumin concentrations were 443 +/- 1029, 394 +/- 749 and 20 +/- 33 mg/l (p < 0.01 vs. diabetics type 2). There was a correlation between urinary VEGF and albumin, but only in patients with type 2 diabetes (R = 0.497; n = 36; p = 0.002). Urinary VEGF(165) was similar in patients with (n = 40) and without ACE inhibitor/AT1 antagonist therapy (n = 32) and in normal volunteers, whereas serum VEGF(165) was higher in the treated type 1 diabetics. CONCLUSIONS: These results may suggest that VEGF(165) plays some role in the development of albuminuria in diabetic nephropathy due to type 2 but not type 1 diabetes.

Adult↗
PubMed2002

Cross-sectional investigation on the accuracy of alternate site glucose testing using the Soft-Sense glucose meter.

QUESTIONS UNDER STUDY: The aim of this study was to evaluate possible differences in the results of blood glucose testing with the Soft-Sense blood glucose monitoring system (Abbott MediSense, Wiesbaden, Germany; not yet available in Switzerland) using different sites for drawing whole blood samples. METHODS: In total, 66 patients participated in the study. Blood glucose measurements were performed with the Soft-Sense device taking capillary blood from the forearm and the fingertip. The results were compared with blood glucose measurements by means of a laboratory reference method using blood from the fingertips. RESULTS: 276 blood glucose data sets could be obtained and were used for the examination of the accuracy of blood glucose measurements at both different sites. Blood glucose results obtained from the arm with Soft-Sense correlated well and were nearly parallel with the results achieved from the fingertip with a laboratory reference method (regression analysis: slope = 0.981; intercept = 0.045 mmol/l (0.819 mg/dl); correlation coefficient r = 0.943). Error grid analysis showed 99.2% of the measurements within clinically acceptable zones A and B. In addition, finger stick measurements done with the Soft-Sense device and the reference method revealed a strong correlation (regression analysis: slope = 0.959; intercept = -0.042 mmol/l (0.748 mg/dl); correlation coefficient r = 0.972). Error grid analysis showed 98.9% of all blood glucose readings within clinically acceptable zones A and B. Mean absolute percent deviations were 9.3+/- 8.1% for the finger tests and 11.2+/- 8.7% for the arm tests. If blood glucose values exceeded 11.1 mmol/l (200 mg/dl), measurements revealed from the forearm were slightly lower than the measurements obtained from the fingertips. CONCLUSIONS: The results indicate that the automated blood glucose monitoring device Soft-Sense provides accurate results independent of the measuring site. As with other alternate site testing devices, nearly painless blood collection at the forearm might help to increase patients readiness to perform more frequent measurements by self blood glucose monitoring, which is a known prerequisite of improved blood glucose control.

Bias↗
PubMed2002

Evaluation of a computer based interactive diabetes education program designed to train the estimation of the energy or carbohydrate contents of foods.

The objective of this study was to evaluate a computer based interactive diabetes education program designed to train patients with diabetes to correctly estimate the energy or carbohydrate contents of foods. The acceptance and the operator convenience of the program were evaluated with an integrated program and written questionnaires. The training success was calculated for each user from the data sets after multiple repetitions of the same exercise. Age, weight, type of diabetes, previous training and computer experience of 126 patients with type 1 or 2 diabetes from three different German diabetes centres were documented. The evaluation of the computer program indicated a good acceptance and operator convenience. Moreover, there was a significant training success in patients who have never used a structured diabetes education program before. Therefore, the potential impact of the program is to support but not to replace structured diabetes education programs and to further motivate and attract patients to diabetes education programs.

Computer-Assisted Instruction↗