F Schulze

Publications (2)4.71 Total impact

• Article: Asymmetric dimethylarginine is associated with parameters of glucose metabolism in Caucasian but not in African women from South Africa.

  M Reimann, A E Schutte, N T Malan, P E H Schwarz, R A Benndorf, F Schulze, R H Böger
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  ABSTRACT: Ethnic differences in obesity and obesity related disorders prompted us to search for possible contributors. The impact of the novel cardiovascular risk factor asymmetric dimethylarginine (ADMA) has been never determined in the African population. The present observational study aimed to compare ADMA levels between healthy African (102) and Caucasian women (115) from South Africa, and its impact on glucose metabolism. All participants underwent an oral glucose tolerance test with measurements of glucose, insulin, C-peptide, proinsulin and free fatty acids before and after 30, 60, 90, 120 minutes. Fasting serum ADMA was measured by ELISA assay and obesity was determined by anthropometry. Serum ADMA did not differ between the ethnic groups. After stratification according to ADMA quartiles Caucasian women in the upper quartile had significantly higher body mass index and waist circumference as well as elevated insulin resistance, insulin, C-peptide and proinsulin levels with no differences in serum glucose compared to women in the lowest quartile. There was a significant stronger postchallenge insulin response in Caucasian women of the upper quartile. No differences were found in African women. Despite similar ADMA levels in both ethnic groups ADMA was positively correlated with parameters of glucose metabolism in the Caucasian but not in the African women from South Africa.
  Experimental and Clinical Endocrinology &amp Diabetes 11/2007; 115(9):600-5. · 1.69 Impact Factor
• Article: Determination of a reference value for N(G), N(G)-dimethyl-L-arginine in 500 subjects.

  F Schulze, R Maas, R Freese, E Schwedhelm, E Silberhorn, R H Böger
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  ABSTRACT: Asymmetric dimethylarginine (ADMA) acts as an endogenous inhibitor of NO-synthase. In the last years ADMA has emerged as a cardiovascular risk factor. The aim of this study was to determine a reference value for ADMA. Plasma samples of 500 healthy subjects in the 19-75 year age group were analyzed. Exclusion criteria from this study were smoking, any known significant disease, body-mass-index (BMI) above 30 kg m(-2), elevated plasma lipid levels, impaired renal function, hypertension, and intake of any medication. The ADMA levels were determined by ELISA, (DLD Diagnostics, Hamburg, Germany). Mean ADMA plasma concentration of the total population was 0.69 micromol L(-1) (SD 0.20) and 95% of the measured values were in the range from 0.36 micromol L(-1) to 1.17 micromol L(-1). Women below 50 years of age had lower ADMA levels than men below 50 years of age [0.62 (0.17) micromol L(-1) vs. 0.69 (0.19) micromol L(-1); P = 0.001] and woman above 50 years of age had higher ADMA levels than men above 50 years of age [0.80 (0.22) micromol L(-1) vs. 0.73 (0.20) micromol L(-1); P = 0.036]. A regression analysis of ADMA levels and age was performed for each sex. The regression factor was r = 0.444 for women in a squared regression model (P < 0.001) and r = 0.212 for men in a linear regression model (P < 0.001). The study was able to define a reference value for ADMA plasma levels with 0.36-1.17 micromol L(-1) and found sex dependent correlations between ADMA and age. Women showed a significant increase in ADMA plasma levels with onset of menopause.
  European Journal of Clinical Investigation 10/2005; 35(10):622-6. · 3.02 Impact Factor