TABLE 2.

Mean Levels of Blood Pressure and Prevalence of Obesity and High Blood Pressure in Various Examinations

Race–Gender	Examination Period	n	Obese, %	BMI z Score	SBP, mm Hg	SBP z Score	DBP, mm Hg	DBP z Score	High Blood Pressure, %a
White boys	1974–1977	2497	7.5	0.02	101 ± 10	−0.32	62 ± 9	0.05	4.6
	1979–1985	3283	9.1	0.19*	104 ± 11*	−0.16*	62 ± 9	0.06	5.6
	1988–1993	1845	16.3*	0.42*	102 ± 10	−0.35	60 ± 9*	−0.12*	3.2
Black boys	1974–1977	1411	5.2	−0.09	101 ± 11	−0.37	62 ± 9	0.08	6.4
	1979–1985	1868	7.7	0.09*	104 ± 12	−0.23*	62 ± 9	0.05	3.3
	1988–1993	1314	12.1*	0.37*	102 ± 12	−0.34	60 ± 10*	−0.14*	4.6
White girls	1974–1977	2317	4.6	−0.04	100 ± 10	−0.27	62 ± 9	0.09	7.3
	1979–1985	3161	7.9*	0.12*	103 ± 10	−0.07*	64 ± 9	0.22*	9.4
	1988–1993	1804	14.4*	0.37*	101 ± 10	−0.28	61 ± 10*	−0.04*	5.2
Black girls	1974–1977	1329	7.8	0.07	101 ± 11	−0.29	63 ± 10	0.12	8.4
	1979–1985	1907	9.8	0.22	103 ± 11*	−0.09*	64 ± 9	0.19	10.6
	1988–1993	1356	14.8*	0.40*	101 ± 11	−0.30	61 ± 10*	-0.09*	5.7

^aAn SBP or DBP that was ≥90th percentile of the Fourth Report.²⁵

*P < .001 as assessed in race- and gender-specific regression models (linear or logistic) that assessed whether the mean (or prevalence) in the second and third time periods differed from the level in 1974–1977. All models accounted for the nonlinear effects of age, as well as for the intercorrelations among subjects who were examined >1 time.