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Figure 2 CHGA and Catecholamine Secretion: BP, Sex, and the 3'-UTR

(A) Hypertension, sex, and CHGA secretion. Resting plasma concentration of the CHGA precursor (epitope: CHGA _116-439) was measured in plasma from seated human subjects with normal renal function (serum creatinine 1.5 mg/dl). We studied subjects with a diagnosis of essential hypertension (HT), versus unmedicated control subjects (NT) with normal blood pressure (BP). (B) Hypertension, sex, and catecholamine secretion. The same individuals were studied for plasma norepinephrine concentration (CHGA and norepinephrine were measured in the same plasma sample). (C) CHGA as a predictor of catecholamine secretion. Individuals were divided into quantiles above and below the median value for plasma CHGA concentration, and plasma catecholamine concentrations were calculated in the 2 groups (CHGA and catecholamine were measured in the same plasma sample). (D) CHGA 3'-untranslated region (3'-UTR) variant C+87T: influence on circulating CHGA. Resting plasma concentration of the CHGA precursor (epitope: CHGA _116-439) was measured in plasma from 578 genotyped white subjects (187 men, 391 women). Each subject had normal renal function (serum creatinine 1.5 mg/dl). Since the distribution of plasma CHGA _116-439 concentration in this sample deviated substantially from normality (skewness = 6.03 ± 0.10, kurtosis = 55.2 ± 0.20), we used a nonparametric median test (evaluating whether 2 or more independent samples [defined by diploid genotype] are drawn from populations with the same median, using the chi-square statistic). There was no gene-by-sex interaction on the CHGA trait (p = 0.57). HWE = Hardy-Weinberg equilibrium; other abbreviations as in Figure 1.