Table 4.
Predictors of overweight and high %BF from univariate logistic regression analyses for 18-year-old men and women, Johannesburg–Soweto, South Africa, Birth to Twenty Plus (Bt20+) cohort
| Overweight† (men) | Overweight† (women) | High %BF‡ (men) | High BF‡ (women) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | % | OR | 95 % CI | n | % | OR | 95 % CI | n | % | OR | 95 % CI | n | % | OR | 95 % CI | |
| Intrinsic factors | ||||||||||||||||
| Age (years) | 758 | P=0·201 | 934 | P=0·30 | 338 | P=0·69 | 764 | P=0·19 | ||||||||
| 17–18 years§ | 267 | 8·6 | 1·00 | – | 385 | 31·2 | 1·00 | – | 140 | 12·1 | 1·00 | – | 355 | 30·1 | 1·00 | – |
| ≥18 years | 491 | 11·6 | 1·39 | 0·84, 2·32 | 549 | 28·0 | 0·86 | 0·65, 1·14 | 198 | 13·6 | 1·14 | 0·60, 2·18 | 409 | 25·9 | 0·81 | 0·59, 1·11 |
| Population group | 750 | P=0·001** | 924 | P=0·14 | 329 | P=0·001** | 757 | P=0·16 | ||||||||
| Black African§ | 620 | 8·4 | 1·00 | – | 774 | 30·4 | 1·00 | – | 281 | 11·0 | 1·00 | – | 640 | 14·6 | 1·00 | – |
| White | 63 | 22·2 | 3·12 | 1·61, 6·03 | 61 | 31·1 | 1·04 | 0·59, 1·82 | 23 | 0·0 | – | – | 41 | 28·7 | 0·42 | 0·17, 1·03 |
| Mixed ancestry | 67 | 16·4 | 2·14 | 1·06, 4·35 | 89 | 20·2 | 0·58 | 0·34, 0·99 | 25 | 36·0 | 4·54 | 1·85, 11·1 | 76 | 26·3 | 0·88 | 0·52, 1·52 |
| Low birth weight (<2500 g) | 706 | P=0·08 (*) | 869 | P=0·17 | 336 | P=0·52 | 761 | P=0·27 | ||||||||
| No§ | 649 | 11·4 | 1·00 | – | 769 | 30·7 | 1·00 | – | 313 | 13·4 | 1·00 | – | 670 | 29·7 | 1·00 | – |
| Yes | 57 | 3·5 | 0·28 | 0·07, 1·18 | 100 | 24·0 | 0·71 | 0·44, 1·16 | 23 | 8·7 | 0·61 | 0·14, 2·72 | 91 | 23·1 | 0·75 | 0·44, 1·25 |
| Pubertal development | 622 | P=0·489 | 825 | P<0·0001*** | 308 | P=0·36 | 732 | P=0·001** | ||||||||
| Early stage§,|| | 87 | 8·1 | 1·00 | – | 367 | 36·5 | 1·00 | – | 38 | 15·8 | 1·00 | – | 325 | 34·5 | 1·00 | – |
| Late stage¶ | 535 | 10·5 | 1·34 | 0·59, 3·03 | 458 | 24·5 | 0·56 | 0·42, 0·76 | 270 | 10·7 | 0·64 | 0·25, 1·66 | 407 | 23·3 | 0·58 | 0·42, 0·80 |
| Household socio-economic factors | ||||||||||||||||
| Caregiver education | 683 | P=0·001** | 837 | P=0·67 | 795 | P=0·37 | 678 | P=0·24 | ||||||||
| ≤Primary school | 97 | 8·3 | 0·32 | 0·13, 0·77 | 119 | 29·4 | 1·22 | 0·69, 2·16 | 120 | 24·2 | 1·20 | 0·63, 2·27 | 90 | 10 | 0·49 | 0·21, 1·13 |
| Secondary school | 490 | 9·0 | 0·35 | 0·20, 0·62 | 596 | 29·4 | 1·22 | 0·78, 1·90 | 575 | 27·3 | 1·41 | 0·84, 2·36 | 480 | 14·2 | 0·73 | 0·42, 1·26 |
| Higher education§ | 96 | 21·9 | 1·00 | – | 122 | 25·4 | 1·00 | – | 100 | 21·0 | 1·00 | – | 108 | 18·5 | 1·00 | – |
| Household wealth index | 675 | P=0·0002*** | 821 | P=0·25 | 297 | P=0·007** | 674 | P=0·22 | ||||||||
| 1st tertile | 230 | 6·1 | 0·30 | 0·16, 0·58 | 285 | 25·6 | 0·77 | 0·53, 1·12 | 96 | 6·2 | 0·24 | 0·09, 0·62 | 224 | 24·1 | 0·78 | 0·51, 1·18 |
| 2nd tertile | 223 | 8·1 | 0·41 | 0·23, 0·75 | 274 | 31·4 | 1·02 | 0·71, 1·47 | 105 | 11·4 | 0·46 | 0·21, 0·99 | 233 | 31·3 | 1·11 | 0·74, 1·67 |
| 3rd tertile (high)§ | 222 | 17·6 | 1·00 | – | 262 | 30·9 | 1·00 | – | 96 | 21·9 | 1·00 | – | 217 | 29·0 | 1·00 | – |
| Adolescent smoking status | 558 | P=0·435 | 715 | P=0·44 | 271 | P=0·19 | 633 | P=0·67 | ||||||||
| Never smoked§ | 138 | 11·6 | 1·00 | – | 278 | 32·4 | 1·00 | – | 77 | 11·7 | 1·00 | – | 242 | 27·3 | 1·00 | – |
| Previous smoker | 173 | 13·3 | 1·17 | 0·59, 2·31 | 270 | 27·4 | 0·79 | 0·55, 1·14 | 92 | 18·5 | 1·71 | 0·72, 4·09 | 245 | 30·6 | 1·17 | 0·79, 1·74 |
| Current smoker | 247 | 9·3 | 0·78 | 0·40, 1·54 | 167 | 30·5 | 0·92 | 0·61, 1·39 | 102 | 9·8 | 0·82 | 0·32, 2·13 | 146 | 27·4 | 1·00 | 0·63, 1·59 |
| Neighbourhood socio-economic factors | ||||||||||||||||
| Neighbourhood economic index | 709 | P=0·085(*) | 878 | P=0·29 | 309 | P=0·65 | 718 | P=0·54 | ||||||||
| 1st tertile | 233 | 10·7 | 0·77 | 0·40, 1·34 | 331 | 31·4 | 1·01 | 0·72, 1·42 | 102 | 12·8 | 1·13 | 0·49, 2·61 | 284 | 28·9 | 0·98 | 0·67, 1·44 |
| 2nd tertile | 224 | 7·1 | 0·49 | 0·26, 0·92 | 265 | 26·0 | 0·78 | 0·53, 1·13 | 102 | 15·7 | 1·44 | 0·64, 3·22 | 201 | 25·0 | 0·80 | 0·52, 1·23 |
| 3rd tertile (high)§ | 252 | 13·5 | 1·00 | – | 282 | 31·2 | 1·00 | – | 105 | 11·4 | 1·00 | – | 233 | 29·2 | 1·00 | – |
| Neighbourhood availability of services index | 706 | P=0·34 | 878 | P=0·50 | 306 | P=0·92 | 718 | P=0·75 | ||||||||
| 1st tertile | 228 | 8·3 | 0·74 | 0·40, 1·37 | 300 | 32·0 | 1·19 | 0·83, 1·71 | 95 | 13·7 | 1·16 | 0·51, 2·64 | 254 | 27·9 | 0·96 | 0·65, 1·44 |
| 2nd tertile | 231 | 12·5 | 1·17 | 0·67, 2·04 | 309 | 28·2 | 0·99 | 0·69, 1·43 | 103 | 13·6 | 1·15 | 0·51, 2·58 | 241 | 25·7 | 0·86 | 0·57, 1·29 |
| 3rd tertile (high)§ | 247 | 10·9 | 1·00 | – | 269 | 28·3 | 1·00 | – | 108 | 12·0 | 1·00 | – | 223 | 28·7 | 1·00 | – |
| Neighbourhood problem index | 704 | P=0·082(*) | 868 | P=0·93 | 304 | P=0·97 | 709 | P=0·86 | ||||||||
| 1st tertile | 228 | 7·9 | 0·52 | 0·28, 0·95 | 287 | 30·0 | 1·07 | 0·75, 1·53 | 99 | 14·1 | 1·08 | 0·49, 2·40 | 241 | 27·8 | 1·07 | 0·71, 1·60 |
| 2nd tertile | 244 | 9·8 | 0·66 | 0·37, 1·15 | 280 | 29·3 | 1·03 | 0·72, 1·48 | 99 | 13·1 | 0·99 | 0·44, 2·23 | 230 | 28·7 | 1·12 | 0·74, 1·68 |
| 3rd tertile (low)§ | 232 | 14·2 | 1·00 | – | 301 | 28·6 | 1·00 | – | 106 | 13·2 | 1·00 | – | 238 | 26·5 | 1·00 | – |
| Neighbourhood social support index | 710 | P=0·99 | 877 | P=0·69 | 311 | P=0·17 | 718 | P=0·046* | ||||||||
| 1st tertile | 217 | 10·6 | 0·99 | 0·55, 1·79 | 321 | 28·0 | 0·86 | 0·60, 1·22 | 97 | 18·6 | 2·05 | 0·91, 4·59 | 265 | 27·2 | 1·26 | 0·84, 1·91 |
| 2nd tertile | 249 | 10·8 | 1·02 | 0·58, 1·80 | 287 | 30·0 | 0·94 | 0·66, 1·35 | 104 | 11·5 | 1·17 | 0·49, 2·79 | 229 | 33·2 | 1·68 | 1·11, 2·55 |
| 3rd tertile (favourable)§ | 244 | 10·7 | 1·00 | – | 269 | 31·2 | 1·00 | – | 110 | 10·0 | 1·00 | – | 224 | 22·8 | 1·00 | – |
| Place of residence | 623 | P=0·031* | 749 | P=0·80 | 271 | P=0·18 | 620 | P=0·61 | ||||||||
| Soweto§ | 518 | 9·1 | 1·00 | – | 606 | 29·0 | 1·00 | – | 228 | 14·9 | 1·00 | – | 505 | 27·5 | 1·00 | – |
| Metropolitan Johannesburg | 105 | 16·2 | 1·94 | 1·06, 3·52 | 143 | 28·0 | 0·95 | 0·63, 1·42 | 43 | 7·0 | 0·43 | 0·12, 1·46 | 115 | 25·2 | 0·89 | 0·56, 1·41 |
%BF, percentage body fat.
(*) P<0·10, *P<0·05, **P<0·01, ***P<0·001.
†
Overweight was defined using age- and sex-specific international cut-offs for BMI for <18 years( 46 ) and ≥18 years( 48 ).
‡
High %BF was defined as fat mass ≥85·01th percentile( 49 ).
§
Reference category.
||
In men, early stage of pubertal development refers to Tanner stages 2–3 (late maturers). In women, it refers to age of entry into menarche <13 years (early maturers).
¶
In men, late stage of pubertal development refers to Tanner stages 4–5 (early maturers). In women, it refers to age of entry into menarche ≥13 years (late maturers).