Ambulatory Blood Pressure Profiles and Correlation with Cardiovascular Risk Factors in a Sample of 390 University Employees in Tanzania

Figures & data

Table 1 Demographic and Clinical Characteristic of Study Participants

Characteristics	n (%) or Mean ±SD
Age (years)	40.5 ± 8.9
Age groups (years); n (%)
<30	67 (17.2)
31–40	138 (35.4)
41–50	126 (32.3)
>50	59 (15.1)
Work station; n (%)
Mloganzila campus	85 (21.8)
Muhimbili campus	305 (78.2)
Education level; n (%)
Primary	15 (3.8)
Secondary	59 (15.1)
College/University	316 (81)
Staff category; n (%)
Academic staff and Doctors	66 (16.9)
Nurses	54 (13.8)
Administrative and Technical staff	270 (69.2)
Marital status; n (%)
Single	94 (24.1)
Married	280 (71.8)
Divorced/Widowed	16 (4.1)
Weight (kg)	68.9 ± 11.3
Height (m)	1.60 ± 0.06
Body Mass Index (kg/m^2)	27.1 ± 4.6
Obesity status; n (%)
Normal	125 (32.0)
Overweight	140 (35.9)
Obese	125 (32.1)
Positive family history of hypertension; n (%)	138 (35.4)
Known hypertensive; n (%)	61 (15.6)
Known diabetic; n (%)	8 (2.1)
Consuming alcohol; n (%)	172 (44.1)
Ever smoked; n (%)	13 (3.3)

Table 2 Laboratory Findings of Study Participants

Laboratory Findings	n (%) or Mean ±SD
Fasting blood glucose (mmol/l)	4.5 ± 0.6
Proportions with diabetes mellitus n (%)	13 (3.3)
Total serum cholesterol (mmol/l)	4.5 ± 0.9
Proportions with raised total cholesterol n (%)	92 (23.6)
Serum HDL-Cholesterol (mmol/l)	1.19 ± 0.13
Serum LDL-Cholesterol (mmol/l)	2.4 ± 0.4
Proportion with raised LDL-Cholesterol, n (%)	18 (4.6)
Serum Triglycerides (mmol/l)	1.53 ± 0.27
Proportion with raised Triglycerides, n (%)	87 (22.3)
Serum Uric acid (mmol/l)	0.36 ± 0.12
Proportions with hyperuricemia, n (%)	53 (13.6)
Serum Blood Urea Nitrogen (mmol/l)	3.96 ± 0.93
Serum Creatinine (µmol/l)	86.3 ± 17.4
Estimated GFR (mL ∕min ∕1.73 m2)	94.9 ± 23.3
Proportions with eGFR <60, n (%)	17 (4.4%)

Abbreviations: HDL, high density lipoprotein; LDL, low density lipoprotein; eGFR, estimated glomerular filtration rate.

Table 3 Office and 24-Hour Ambulatory Blood Pressure Findings of Study Participants

BP Findings	Men (n = 209)	Women (n = 181)	Total (N = 390)	*p-value
Office Systolic BP (mmHg)	128 ± 12	124 ± 13	126 ± 12	0.001
Office Diastolic BP (mmHg)	80 ± 14	76 ±11	78 ±13	0.004
Daytime Systolic BP (mmHg)	129 ±12	123 ±11	126 ± 12	<0.001
Daytime Diastolic BP (mmHg)	79 ± 10	75 ± 10	77 ± 10	<0.001
Sleep time Systolic BP (mmHg)	121 ± 17	116 ± 17	118 ± 18	0.006
Sleep time Diastolic BP (mmHg)	74 ± 11	70 ± 13	72 ± 12	0.002
24-hour Systolic BP (mmHg)	125 ± 13	119 ± 14	122 ± 14	<0.001
24-hour Diastolic BP (mmHg)	77 ± 10	72 ± 11	75 ± 10	<0.001
Participants with Office hypertension, n (%)	49 (23.4)	33 (18.2)	82 (21.0)	0.208
Participants with Ambulatory Daytime hypertension, n (%)	46 (22.0)	18 (9.9)	64 (16.4)	0.001
Participants with 24-hr hypertension, n (%)	101 (48.3)	53 (29.3)	154 (39.5)	<0.001
Participants with nocturnal hypertension, n (%)	136 (65.1)	78 (43.1)	214 (54.9)	<0.001
Participants with isolated nocturnal hypertension, n (%)	91 (43.5)	66 (36.5)	157 (40.3)	0.155
Participants with white coat hypertension, n (%)	30 (14.4)	33 (18.2)	63 (16.2)	0.299
Participants with masked hypertension, n (%)	27 (12.9)	18 (9.9)	45 (11.5)	0.359
Participants with nocturnal non-dipping, n (%)	133 (63.6)	127 (70.2)	260 (66.7)	0.173
Participants with extreme dipping, n (%)	23 (11.0)	20 (11.0)	43 (11.0)	0.989
Participants with reverse dipping, n (%)	55 (26.3)	39 (21.5)	94 (24.1)	0.272
Participants with normal dipping, n (%)	52 (24.9)	28 (15.5)	80 (20.5)	0.022

Notes: Results are mean ± SD unless stated otherwise; *p-value, comparing differences between men and women.

Figure 1 (A) Univariate correlates of office, day-time, sleep and 24-hour mean systolic BP. (B) Univariate correlates of office, day-time, sleep and 24-hour mean diastolic BP.

Table 4 Correlates of Ambulatory Day-Time Mean Systolic and Diastolic Blood Pressure

Factors	Mean Daytime SBP		Mean Daytime DBP
	r	p-value	r	p-value
Age (years)	0.323	<0.001	0.247	<0.001
Weight (kg)	0.256	<0.001	0.206	<0.001
Height (m)	−0.094	0.065	−0.078	0.126
BMI (kg/m^2)	0.286	<0.001	0.219	<0.001
Waist circumference	0.139	0.006	0.088	0.081
Fasting Blood Sugar (mmol/l)	0.446	<0.001	0.316	<0.001
Total Cholesterol (mmol/l)	0.707	<0.001	0.49	<0.001
HDL-Cholesterol (mmol/l)	0.733	<0.001	0.306	<0.001
LDL-Cholesterol (mmol/l)	0.439	<0.001	0.351	<0.001
Triglyceride (mmol/l)	0.49	<0.001	0.285	<0.001
Uric acid (mmol/l)	0.652	<0.001	0.496	<0.001
Serum Creatinine (µmol/l)	0.67	<0.001	0.439	<0.001
eGFR (mL ∕min ∕1.73m2)	−0.362	<0.001	−0.208	<0.001
Urea Nitrogen (µmol/l)	0.465	<0.001	0.284	<0.001

Abbreviations: HDL, high density lipoprotein; LDL, low density lipoprotein; eGFR, estimated glomerular filtration rate.

Table 5 Socio-Demographic, Clinical and Laboratory Findings in Study Participants with and without Hypertension

Characteristics	Non-Hypertensive (n = 300)	Hypertensive (n = 90)	p-value
Women, n (%)	150 (50)	31 (34.4)	0.009
Age (years)	38.5 ± 8.6	47.2 ± 6.1	<0.001
Staff category, n (%)
Nurses	47 (15.7)	7 (7.8)	0.02
Academic staff and Doctors	56 (18.7)	10 (11.1)
Administrative and Technical staff	197 (65.7)	73 (81.1)
Marital status, n (%)
Single	82 (27.3)	12 (13.3)	<0.001
Married	214 (71.3)	66 (73.3)
Divorced/widowed	4 (1.3)	12 (13.3)
Family history of hypertension, n (%)	79 (26.3)	59 (65.6)	<0.001
Ever smoked, n (%)	5 (1.7)	8 (8.9)	0.001
Consuming alcohol, n (%)	127 (42.3)	45 (50.0)	0.199
Body Mass Index (kg/m^2)	26 ± 4.2	31 ± 3.8	<0.001
Obesity class, n (%)
Normal weight	125 (41.7)	0 (0.0)	<0.001
Overweight	114 (38.0)	26 (28.9)
Obese	61 (20.3)	64 (71.1)
Waist circumference (cm)	88 ± 8	92 ± 7	<0.001
Raised waist circumference, n (%)	51 (17.0)	27 (30.0)	0.007
Fasting Blood Glucose (mmol/l)	4.4 ± 0.3	4.9 ± 1.0	<0.001
Raised glucose, n (%)	0 (0.0)	13 (14.4)	<0.001
Total Cholesterol (mmol/l)	4.3 ± 0.5	5.4 ± 1.1	<0.001
Raised Total Cholesterol, n (%)	31 (10.3)	61 (67.8)	<0.001
Triglycerides (mmol/l)	1.46 (0.17)	1.76 (0.37)	<0.001
Raised Triglycerides level, n (%)	43 (14.3)	44 (48.9)	<0.001
Uric Acid level (mmol/l)	0.32 ± 0.08	0.48 ± 0.16	<0.001
Raised Uric Acid, n (%)	12 (4.0)	41 (45.6)	<0.001
Serum Creatinine (µmol/l)	82 ± 12	102 ± 23	<0.001
eGFR (mL ∕min ∕1.73m2)	99 ± 21	80 ± 26	<0.001
Proportion with eGFR <60, n (%)	6 (2.0)	11 (12.2)	<0.001

Note: Results are mean ± SD, unless stated otherwise.

Abbreviation: eGFR, estimated glomerular filtration rate.

Table 6 Independent Associations of Hypertension Among MUHAS Employees Obtained in Multivariate Logistic Regression Analysis

Variables	Odds Ratio	95% CI	p-value
Male gender	7.96	2.50–25.30	<0.001
Age ≥40 years	3.94	1.66–9.33	0.002
Positive family history of hypertension	5.60	2.61–12.04	<0.001
Central obesity	8.98	2.72–29.70	<0.001
Ever smoked	0.42	0.08–2.20	0.301
Elevated total cholesterol	3.84	1.56–9.50	0.004
Elevated uric acid	7.90	2.55–24.43	<0.001