title: Antioxidants modify the relationship between endothelin-1 level and glucose metabolism-associated parameters.
abstract: Glucose handling impairment and oxidative stress are implicated in the overexpression of endothelin-1 (ET-1). The objective of the study was to assess possible interplay of the 2 systems in relation to ET-1 in clinical setting. In hypertensive outpatients, on top of typical clinical workup, we assessed ET-1 levels, glucose handling parameters (glycated hemoglobin [HbA(1c)], homeostasis model assessment [HOMA] index, and insulin level), and antioxidative protection (ferric reducing ability of plasma [FRAP], superoxide dismutase [SOD], and vitamin C). Average age of 68 patients (64% women, 50% diabetic, 40% smokers) was 67.7 (10.6) years. Serum ET-1 level averaged 1.09 (0.48) pg/mL and correlated positively with glucose handling-associated parameters (insulin, r = 0.22; HOMA, r = 0.21; HbA(1c), r = 0.23; all Ps < .05) and negatively with constituents of antioxidative protection system (FRAP, r = -0.45; SOD, r = -0.47; both Ps < .0001; vitamin C, r = -0.27; P < or = .01). In sex-, age-, blood pressure-, and creatinine-adjusted models, with interchangeable introduction of antioxidative parameters on top of interchangeable introduction of glucose handling-associated parameters, ET-1 levels were each time only significantly associated with FRAP in the context of HbA(1c); FRAP, SOD, or vitamin C in the context of HOMA; and FRAP or SOD in the context of insulin concentration. In the stepwise regression with the above parameters offered, only FRAP and vitamin C were associated with ET-1 level. In treated hypertensive patients, impaired glucose handling is associated with higher ET-1 levels. This statistical relation is blunted in the context of parameters of antioxidative protection. The hypothesis that poor antioxidation is mediating the effect of impaired glucose handling on ET-1 levels needs further confirmation.
authors.affiliation: Department of Internal Medicine and Gerontology, Jagiellonian University Medical College, 31-531 Kraków, Poland. anskal@su.krakow.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Skalska
authors.forename: Jerzy
authors.initials: J
authors.lastname: Gasowski
authors.forename: Tomasz
authors.initials: T
authors.lastname: Grodzicki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000378:metabolism / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D048909:Diabetes Complications / Q000097:blood / Q000378:metabolism; D019332:Endothelin-1 / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D005947:Glucose / Q000378:metabolism*; D006442:Glycated Hemoglobin / Q000032:analysis; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000378:metabolism; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D019332:Endothelin-1; D005947:Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human