Table 2.
Factors investigated for association with diastolic blood pressure among adolescents from the Entebbe Mother and Baby Study (N = 1119)
| Factors | Mean BP (SD) | Crude β (95% CI) | P-value | Adjusted β (95% CI) | P-value |
|---|---|---|---|---|---|
| Level 1: Maternal factors | |||||
| Age (years) | 0.08 (−0.00, 0.15) | 0.058 | 0.05 (−0.03, 0.13) | 0.247 | |
| Household socioeconomic index (n = 1104) | 0.22 (−0.13, 0.56) | 0.225 | |||
| Parity | 0.08 (−0.16, 0.32) | 0.530 | |||
| Body mass index (n = 1110) | 0.16 (0.03, 0.29) | 0.014 | 0.14 (0.01, 0.27) | 0.030 | |
| Education status | |||||
| None (n = 28) | 65.1 (9.3) | 0.44 (−2.32, 3.19) | 0.08 (−2.71, 2.89) | ||
| Primary (n = 542) | 64.6 (6.7) | Reference | Reference | ||
| Senior (n = 438) | 65.5 (7.5) | 0.92 (0.01, 1.84) | 1.00 (0.07, 1.92) | ||
| Tertiary (n = 109) | 66.8 (8.0) | 2.14 (0.65, 3.64) | 0.023 | 2.08 (0.57, 3.59) | 0.022 |
| Marital status | |||||
| Single (n = 116) | 64.2 (6.4) | −1.19 (−2.59, 0.21) | −1.26 (−2.69, 0.16) | ||
| Married/cohabiting (n = 967) | 65.4 (7.4) | Reference | Reference | ||
| Separated/widowed (n = 35) | 63.5 (6.0) | −1.91 (−4.36, 0.54) | 0.089 | −1.91 (−4.38, 0.54) | 0.075 |
| Area of residence | |||||
| Urban (n = 770) | 65.3 (7.5) | Reference | |||
| Rural (n = 336) | 64.9 (6.8) | 0.49 (−1.42, 0.44) | 0.302 | ||
| Alcohol use | |||||
| No (n = 775) | 65.3 (7.5) | Reference | |||
| Yes (n = 343) | 65.0 (6.6) | −0.34 (−1.26, 0.59) | 0.477 | ||
| Infections | |||||
| HIV | |||||
| Uninfected (n = 1002) | 65.2 (7.3) | Reference | |||
| Infected (n = 117) | 64.9 (6.5) | −0.35 (−1.74, 1.05) | 0.626 | ||
| Asymptomatic malaria | |||||
| Uninfected (n = 991) | 65.2 (7.4) | Reference | |||
| Infected (n = 109) | 64.9 (6.6) | −0.29 (−1.73, 1.15) | 0.695 | ||
| Schistosoma mansoni | |||||
| Uninfected (n = 908) | 65.2 (7.1) | Reference | |||
| Infected (n = 204) | 65.5 (7.7) | 0.31 (−0.79, 1.41) | 0.579 | ||
| Hookworm (Necator americanus) | |||||
| Uninfected (n = 662) | 65.1 (7.1) | Reference | |||
| Infected (n = 450) | 65.4 (7.4) | 0.27 (−0.60, 1.14) | 0.539 | ||
| Ascaris lumbricoides | |||||
| Uninfected (n = 1084) | 65.3 (7.3) | Reference | |||
| Infected (n = 28) | 65.1 (5.5) | −0.18 (−2.90, 2.54) | 0.896 | ||
| Intervention one | |||||
| Placebo (n = 566) | 65.0 (6.9) | Reference | |||
| Albendazole (n = 553) | 65.4 (7.7) | 0.39 (−0.46, 1.24) | 0.366 | ||
| Intervention two | |||||
| Placebo (n = 564) | 65.4 (7.3) | Reference | |||
| Praziquantel (n = 555) | 65.0 (7.2) | −0.44 (−1.29, 0.42) | 0.315 | ||
| Level 2: Factors in childhood | |||||
| Birth weight (kg) (n = 932) | 0.66 (−0.27, 1.59) | 0.164 | 0.57 (−0.40, 1.53) | 0.246 | |
| Sex | |||||
| Male (n = 583) | 64.9 (7.2) | Reference | Reference | ||
| Female (n = 536) | 65.5 (7.4) | 0.64 (−0.21, 1.49) | 0.141 | 0.49 (−0.43, 1.42) | 0.294 |
| Sickle-cell trait | |||||
| HbAA (n = 661) | 65.4 (7.1) | Reference | |||
| HbAS (n = 141) | 65.5 (7.4) | 0.15 (−1.16, 1.46) | 0.825 | ||
| Season of birth | |||||
| Dry (n = 651) | 65.5 (7.3) | Reference | Reference | ||
| Wet (n = 468) | 64.7 (7.2) | −0.79 (−1.65, 0.07) | 0.073 | 0.59 (−1.52, 0.35) | 0.214 |
| Place of delivery | |||||
| Entebbe Hospital (n = 824) | 65.1 (7.1) | Reference | |||
| Home (n = 120) | 65.4 (8.5) | 0.36 (−1.03, 1.76) | |||
| Others (n = 174) | 65.7 (7.3) | 0.61 (−0.58, 1.80) | 0.564 | ||
| Feeding status (at 6 week of age) | |||||
| Exclusive breast fed (n = 748) | 65.4 (7.4) | Reference | |||
| Mixed fed (n = 344) | 64.7 (7.0) | −0.63 (−1.56, 0.30) | |||
| Weaned (n = 14) | 67.1 (4.4) | 1.78 (−2.07, 5.63) | 0.251 | ||
| Intervention three | |||||
| Placebo (n = 553) | 64.9 (7.0) | Reference | Reference | ||
| Albendazole (n = 554) | 65.5 (7.5) | 0.62 (−0.24, 1.47) | 0.156 | 0.56 (−0.37, 1.48) | 0.233 |
| HIV status | |||||
| Unexposed (n = 1001) | 65.2 (7.3) | Reference | |||
| Exposed not infected (n = 100) | 65.1 (6.7) | −0.12 (−1.62, 1.37) | |||
| Infected (n = 18) | 63.5 (5.1) | −1.71 (−5.10, 1.68) | 0.609 | ||
| Malaria infection below 5 years of age | |||||
| Clinical or asymptomatic malariaa | |||||
| No (n = 456) | 65.9(7.1) | Reference | Reference | ||
| Yes (n = 663) | 64.6 (7.3) | −1.28 (−2.14, −0.41) | 0.004 | −1.47 (−2.41, −0.53) | 0.002 |
| Clinical malariaa | |||||
| None (n = 474) | 66.0 (7.2) | Reference | Reference | ||
| Yes (n = 645) | 64.6 (7.3) | −1.38 (−2.24, −0.51) | 0.002 | −1.33 (−2.26, −0.39) | 0.005 |
| Episodes of clinical malariaa | |||||
| None (n = 474) | 65.9 (7.2) | Reference | Reference | ||
| 1–2 (n = 382) | 64.5 (7.3) | −1.45 (−2.42, −0.47) | −1.53 (−2.59, −0.46) | ||
| ≥3 (n = 263) | 64.9 (7.4) | −1.02 (−2.12, 0.07) | 0.011 | −1.03 (−2.22, 0.16) | 0.015 |
| Asymptomatic malariaa | |||||
| None (n = 983) | 64.5 (7.3) | Reference | Reference | ||
| Yes (n = 124) | 64.9 (7.4) | −1.45 (−2.80, −0.10) | 0.035 | −1.35 (−2.89, 0.18) | 0.082 |
| Schistosoma mansoni | |||||
| Uninfected (n = 1076) | 65.2 (7.3) | Reference | |||
| Infected (n = 33) | 64.5 (5.8) | 0.67 (−3.18, 1.84) | 0.602 | ||
| Ascaris lumbricoides | |||||
| Uninfected (n = 1052) | 65.2 (7.3) | Reference | |||
| Infected (n = 57) | 64.5 (7.1) | −0.75 (−2.68, 1.18) | 0.445 | ||
| Hookworm (Necator americanus) | |||||
| Uninfected (n = 1085) | 65.2 (7.3) | Reference | Reference | ||
| Infected (n = 24) | 62.9 (5.8) | −2.29 (−5.22, 0.64) | 0.125 | −1.79 (−4.93, 1.35) | 0.261 |
| Trichuris trichiura | |||||
| Uninfected (n = 997) | 65.1 (7.2) | Reference | |||
| Infected (n = 112) | 65.8 (7.7) | 0.67 (−0.74, 2.09) | 0.353 | ||
| Microfilaria (Mansonella perstans) | |||||
| Uninfected (n = 1102) | 65.1 (7.2) | Reference | |||
| Infected (n = 8) | 67.3 (3.3) | 2.12 (−2.91, 7.14) | 0.409 | ||
| Level 3: Factors in adolescence | |||||
| Age (years) | 1.85(1.00, 2.70) | <0.001 | 1.53 (0.63, 2.43) | <0.001 | |
| Body mass index (kg/m2) | 0.28 (0.20, 0.36) | <0.001 | 0.74 (0.42, 1.05) | <0.001 | |
| Waist circumference (cm) | 0.88 (0.66, 1.10) | <0.001 | 0.07 (−0.05, 0.18) | 0.279 | |
| Family history | |||||
| High blood pressure | |||||
| No (n = 1000) | 65.0 (7.2) | Reference | Reference | ||
| Yes (n = 105) | 66.7 (7.6) | 1.65 (0.19, 3.12) | 0.027 | 1.57 (0.08, 3.06) | 0.037 |
| Diabetes | |||||
| No (n = 927) | 65.2 (7.2) | Reference | |||
| Yes (n = 186) | 65.5 (7.8) | 0.35 (−0.80, 1.49) | 0.553 | ||
| Body composition analysisc | |||||
| Fat mass indexb (kg/m2) (n = 176) | 1.75 (0.83, 2.69) | <0.001 | 0.87 (−0.73, 2.47) | 0.255 | |
| Fat-free mass indexb (kg/m2) (n = 176) | 1.19 (0.40, 1.98) | 0.003 | 0.28 (−0.90, 1.45) | 0.622 | |
| Total body water indexb (kg/m2) (n = 176) | 2.13 (0.95, 3.30) | <0.001 | 1.51 (−0.86, 3.88) | 0.180 | |
| Adding salt to cooked food at the table | |||||
| No (n = 20) | 67.4 (6.1) | 2.19 (−1.04, 5.41) | 2.72 (−0.39, 5.82) | ||
| Yes (n = 1086) | 65.2 (7.3) | Reference | 0.184 | Reference | 0.083 |
| Days a fruit is eaten/week | |||||
| 0–2 (n = 543) | 65.7 (7.1) | Reference | Reference | ||
| 3–7 (n = 541) | 64.7 (7.5) | −0.98 (−1.85, −0.11) | 0.028 | −0.96 (−1.83, −0.10) | 0.027 |
| Days vegetables eaten/week | |||||
| 0–2 (n = 461) | 65.4 (7.1) | Reference | |||
| 3–7 (n = 635) | 65.1 (7.5) | −0.27 (−1.15, 0.60) | 0.540 | ||
| Days animal-protein eaten/week | |||||
| 0–2 (n = 726) | 65.1 (6.9) | Reference | |||
| 3–7 (n = 374) | 65.4 (8.0) | 0.30 (−0.61, 1.20) | 0.523 | ||
| Days sugared drinks taken/week | |||||
| None (n = 427) | 65.0 (7.1) | Reference | Reference | ||
| 1–3 (n = 492) | 65.2 (7.4) | 0.25 (−0.70, 1.20) | 0.12 (−0.84, 1.08) | ||
| 4–7 (n = 174) | 66.0 (7.5) | 1.06 (−0.23, 2.35) | 0.271 | 0.54 (−0.75, 1.83) | 0.707 |
| Days a fruit is eaten/week | |||||
| Days vegetables eaten/week | 0.02 (−0.16, 0.1) | 0.800 | |||
| Days animal-protein eaten/week | 0.14 (−0.11, 0.39) | 0.284 | |||
| Days starchy foods eaten/week | 0.03 (−0.50, 0.55) | 0.924 | |||
| Days sugared drinks taken/week | 0.20 (0.00, 0.41) | 0.048 | |||
| Breast development (girls only)b | |||||
| Pre-pubertal (n = 178) | 64.1 (6.1) | Reference | Reference | ||
| Pubertal (n = 97) | 67.2 (7.9) | 3.067 (1.38, 4.76) | <0.001 | 0.98 (−0.88, 2.84) | 0.281 |
| Pubic hair developmentb | |||||
| Pre-pubertal (n = 441) | 64.1 (6.6) | Reference | Reference | ||
| Pubertal (n = 170) | 66.1 (7.6) | 2.04 (0.82, 3.26) | 0.001 | 0.68 (−0.62, 1.99) | 0.293 |
| Snoring | |||||
| No (n = 932) | 65.1 (7.2) | Reference | |||
| Yes (n = 163) | 65.6 (7.8) | 0.44 (−0.78, 1.66) | 0.477 | ||
| Duration of night sleep | |||||
| <9 hours (n = 306) | 65.8 (7.6) | Reference | Reference | ||
| 9 hours (n = 382) | 64.8 (7.1) | −1.03 (−2.11, 0.06) | −0.92 (−2.02, 0.18) | ||
| >9 hours (n = 405) | 65.2 (7.2) | −0.79(−1.86, 0.28) | 0.160 | −0.67 (−1.76, 0.43) | 0.240 |
| Smoking in household | |||||
| Non (n = 962) | 65.2 (7.3) | Reference | |||
| Yes (n = 147) | 65.0 (6.8) | −0.21 (−1.46, 1.06) | 0.745 | ||
| Type of school attended | |||||
| Day (n = 117) | 65.1 (7.2) | Reference | Reference | ||
| Boarding school (n = 719) | 66.2 (7.8) | 1.13 (−0.26, 2.52) | 0.112 | −0.24 (−1.67, 1.20) | 0.737 |
| Involved in physical education at school | |||||
| No (n = 385) | 65.0 (6.9) | Reference | |||
| Yes (n = 719) | 65.3 (7.5) | 0.32 (−0.58, 1.22) | 0.482 | ||
| Infections at the time of blood pressure measurement | |||||
| Asymptomatic malaria | |||||
| Uninfected (n = 1067) | 65.3 (7.3) | Reference | |||
| Infected (n = 22) | 64.0 (5.5) | −1.31 (−4.36, 1.75) | 0.401 | ||
| Schistosoma mansoni | |||||
| Uninfected (n = 964) | 65.2 (7.4) | Reference | |||
| Infected (n = 112) | 65.0 (5.8) | −0.19 (−1.62, 1.24) | 0.791 | ||
| Hookworm (Necator americanus) | |||||
| Uninfected (n = 1066) | 65.2 (7.3) | Reference | |||
| Infected (n = 10) | 64.0 (5.9) | −1.25 (−5.80, 3.30) | 0.590 | ||
| Ascaris (Ascaris lumbricoides) | |||||
| Uninfected (n = 1073) | 65.2 (7.3) | Reference | |||
| Infected (n = 3) | 62.3 (4.3) | −2.86 (−11.14, 5.42) | 0.498 | ||
| Trichuris trichiura | |||||
| Uninfected (n = 1036) | 65.1 (7.2) | Reference | |||
| Infected (n = 40) | 66.4 (9.4) | 1.23 (−1.07, 3.54) | 0.294 |
Model building followed the hierarchical approach, adding factors sequentially at three levels starting with the distal factors (level 1). Factors at the same level were added to the model at the same time and considered confounders for each other and for proximal factors. A P-value < 0.20 was used for considering the inclusion and maintenance of factors in the model
Adjusted β for which 95% CI exclude 0 are highlighted in bold
β linear regression coefficient: mean difference in blood pressure (BP) measured in mmHg
aNot included in the model together but each was adjusted for all other variables in the model
bNot included in multivariable model building for other exposures because of large proportion of missing information; but each was adjusted for variables in the final model building
cNot adjusted for body mass index because body mass index is on the causal pathway