Prevalence of resistant hypertension in 1810 patients followed up in a specialized outpatient clinic and its association with the metabolic syndrome

Figures & data

Table I. Demographic characteristics of the study population [data are percentages except age and package-years (mean ±SD)].

	Patients with well-controlled hypertension (n = 402)	Patients with uncontrolled hypertension (n = 1,185)	Patients with resistant hypertension (n = 223)	p
Age (years)	55.3 ± 14.4	55.5 ± 13.4	63.8 ± 10.4	< 0.001*
Males	37.8	41.9	36.7	NS
Smoking	23.7	25.3	26.0	NS
Package-years	16 ± 22	11 ± 20	18 ± 22	NS
Type 2 diabetes mellitus	5.1	7.6	15.9	< 0.001
Metabolic syndrome	12.5	16.1	26.4	< 0.001
Normal weight/overweight/obese	23.4/38.3/38.3	15.1/41.9/43.0	6.6/28.6/64.8	< 0.001
Family history of hypertension	22.3	21.9	21.6	NS
Coronary heart disease	6.4	6.8	11.5	< 0.05
Chronic kidney disease	8.3	20.4	23.3	< 0.001
Stroke	4.0	4.3	6.3	NS

NS, not significant. *Post hoc pair-wise comparisons: resistant vs well-controlled, p < 0.001; resistant vs uncontrolled, p < 0.001; uncontrolled vs well-controlled, p = NS.

Table II. Clinical and laboratory characteristics of the study population (data are mean± SD).

	Patients with well-controlled hypertension (n = 402)	Patients with uncontrolled hypertension (n = 1185)	Patients with resistant hypertension (n = 223)	p (overall)	p (for post hoc pair-wise comparisons)
					Resistant vs well-controlled	Resistant vs uncontrolled	Uncontrolled vs well-controlled
SBP (mmHg)	123 ± 9	154 ± 19	156 ± 23	< 0.001	< 0.001	NS	< 0.001
DBP (mmHg)	76 ± 8	93 ± 12	89 ± 14	< 0.001	< 0.001	< 0.001	< 0.001
Heart rate	73 ± 9	76 ± 11	75 ± 11	< 0.001	NS	NS	< 0.001
BMI (kg/m^2)	29.2 ± 6.1	30.1 ± 5.5	31.9 ± 4.9	< 0.005	0.001	< 0.05	NS
Waist (cm)	99 ± 12	100 ± 13	104 ± 15	NS	NA	NA	NA
LDL-C (mg/dl)	141 ± 50	152 ± 57	147 ± 60	NS	NA	NA	NA
HDL-C (mg/dl)	52 ± 13	51 ± 14	50 ± 15	NS	NA	NA	NA
TG (mg/dl)	141 ± 75	157 ± 87	159 ± 75	NS	NA	NA	NA
Glucose (mg/dl)	101 ± 24	106 ± 33	120 ± 38	< 0.001	< 0.001	< 0.001	NS
eGFR (ml/min/1.73 m^2)	79.9 ± 20.4	79.4 ± 24.6	76.4 ± 24.2	NS	NA	NA	NA

NS, not significant; NA, not applicable; SBP, systolic blood pressure; DBP, diastolic blood pressure; BMI, body mass index; LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol; TG, triglycerides; eGFR, estimated glomerular filtration rate.