Nitric oxide levels in patients with diabetes mellitus: A systematic review and meta-analysis.
Altered serum nitric oxide (NO) levels in patients with diabetes mellitus (DM) have been reported by different studies; however, results are still controversial. Until this date, no meta-analysis evaluated the association of NO levels with DM. Thus, this paper describes a meta-analysis conducted to evaluate if there is a relationship between NO levels and type 1 DM (T1DM) or type 2 DM (T2DM).



A literature search was done to identify all studies that investigated NO levels between T1DM or T2DM patients (cases) and non-diabetic subjects (controls). Measurement of nitrate and nitrite (NOx - the stable NO products) were used to estimate NO concentrations because they closely reflect NO bioavailability. Weighted mean differences (WMD) of NOx levels between case and control samples were calculated for T1DM and T2DM groups.



Thirty studies were eligible for inclusion in the meta-analysis (8 in T1DM samples and 22 in T2DM samples). NOx levels were increased in European T1DM patients compared with controls [random effect model (REM) WMD = 8.55, 95% CI 2.88 - 14.21]. No other ethnicity was evaluated in T1DM studies. NOx levels were also increased in both European (REM WMD = 18.76, 95% CI 1.67 - 35.85) and Asian (REM WMD = 18.41, 95% CI 8.01 - 28.81) T2DM patients, but not in Latin American patients compared with controls.



This meta-analysis detected a significant increase in NOx levels in European T1DM patients as well as European and Asian T2DM patients. Further studies in other ethnicities are necessary to confirm these data.
Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-graduation Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Taís S
TS
Assmann
Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
Letícia A
LA
Brondani
Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
Ana P
AP
Bouças
Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-graduation Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Jakeline
J
Rheinheimer
Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-graduation Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Bianca M
BM
de Souza
Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-graduation Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Luís H
LH
Canani
Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
Andrea C
AC
Bauer
Endocrine Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Post-graduation Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address: dcmoreira@hcpa.edu.br.
Daisy
D
Crispim
D000293:Adolescent; D000328:Adult; D002648:Child; D003920:Diabetes Mellitus / Q000097:blood / Q000453:epidemiology; D006801:Humans; D009569:Nitric Oxide / Q000097:blood*; D055815:Young Adult
D009569:Nitric Oxide
Meta-analysis; Nitric oxide levels and diabetes mellitus