Magnitude and predictors of normal-weight central obesity– the AWI-Gen study findings

Figures & data

Table 1. Background characteristics of the study population.

	Categories	Women n (%)	Men n (%)	Total n (%)	P-value
Age groups	40–45 years	397 (54.8%)	327 (45.2%)	724 (36.1%)	0.012
	46–50 years	308 (58.1%)	222 (41.9%)	530 (26.5%)
	51–55 years	230 (52.8%)	206 (47.2%)	436 (21.8%)
	56–60 years	146 (46.7%)	167 (53.3%)	313 (15.6%)
Education	No formal education	118 (76.6%)	36 (23.4%)	154 (7.7%)	0.000
	Primary education	682 (59.3%)	469 (40.8%)	1151 (57.5%)
	Secondary education	277 (41.2%)	395 (58.8%)	672 (33.5%)
	Tertiary education	4 (15.4%)	22 (84.6%)	26 (1.3%)
Ethnicity	Kamba	196 (49.9%)	197 (50.1%)	393 (19.6%)	0.000
	Kikuyu	480 (66.2%)	245 (33.8%)	725 (36.2%)
	Luhya	143 (44.4%)	179 (55.6%)	322 (16.1%)
	Luo	159 (42.5%)	215 (57.5%)	374 (18.7%)
	Others	103 (54.5%)	86 (45.5%)	189 (9.4%)
Employment	Self-employed	632 (66.8%)	314 (33.2%)	946 (47.3%)	0.000
	Employed (Full-time)	50 (18.7%)	217 (81.3%)	267 (13.4%)
	Employed (Part-time)	19 (42.2%)	26 (57.8%)	45 (2.3%)
	Employed (Informal)	287 (46.1%)	336 (53.9%)	623 (31.2%)
	Unemployed	93 (78.2%)	26 (21.8%)	119 (5.9%)
	Total	1,081 (54.0%)	922 (46.0%)	2003 (100.0%)

Table 2. Prevalence of general obesity in the study population by age and sex.

Age groups	Women	Men	Total	P-value
40–45 years	123 (31.0%)	20 (6.1%)	143 (19.8%)	<0.001
46–50 years	93 (30.2%)	4 (1.8%)	97 (18.3%)	<0.001
51–55 years	79 (34.4%)	12 (5.8%)	91 (20.9%)	<0.001
56–60 years	53 (36.3%)	16 (9.6%)	69 (22.0%)	<0.001
Total	348 (32.2%)	52 (5.6%)	400 (20.0%)	<0.001

Table 3. Prevalence of central obesity by age category and gender.

	Age groups	Women n (%)	Men n (%)	Overall n (%)	P-Value
Waist Circumference	40–45 years	275 (69.3%)	70 (21.4%)	345 (47.6%)	<0.001
	46–50 years	232 (75.3%)	46 (20.7%)	278 (52.4%)	<0.001
	51–55 years	182 (83.5%)	47 (22.8%)	239 (54.8%)	<0.001
	56–60 years	118 (80.8%)	62 (37.1%)	180 (57.5%)	<0.001
	Total	817 (75.6%)	225 (24.4%)	1,042 (52.0%)
Waist-to-hip ratio (WHR)	40–45 years	218 (54.9%)	108 (33.0%)	326 (45.0%)	<0.001
	46–50 years	199 (64.6%)	85 (38.3%)	284 (53.6%)	<0.001
	51–55 years	170 (73.9%)	87 (42.2%)	257 (58.9%)	<0.001
	56–60 years	117 (80.1%)	88 (52.7%)	205 (65.5%)	<0.001
	Total	704 (65.1%)	368 (39.9%)	1072 (53.5%)
Visceral Fat Thickness (VFT)	40–45 years	151 (38.0%)	64 (19.6%)	215 (29.7%)	<0.001
	46–50 years	119 (38.6%)	41 (18.6%)	160 (30.1%)	<0.001
	51–55 years	109 (47.4%)	52 (25.2%)	161 (36.9%)	<0.001
	56–60 years	65 (44.5%)	47 (28.1%)	112 (35.8%)	0.001
	Total	444 (41.1%)	204 (22.1%)	648 (32.4%)
Subcutaneous Fat Thickness (SCT)	40–45 years	271 (68.3%)	78 (24.0%)	349 (48.3%)	<0.001
	46–50 years	217 (70.5%)	43 (19.4%)	260 (49.1%)	<0.001
	51–55 years	173 (75.5%)	47 (22.8%)	220 (50.5%)	<0.001
	56–60 years	104 (71.2%)	52 (31.1%)	156 (49.8%)	<0.001
	Overall	765 (70.8%)	220 (23.9%)	985 (49.2%)
	Total (N)	1081	922	2003

n = number of people with central obesity, % = percent with central obesity among same gender and age group, N = total sample size, p-values = are from chi-square test of association between central obesity and gender within each age category.

Table 4. Prevalence of central obesity by BMI categories and gender.

	BMI status	Women n (%)	Men n (%)	Total n (%)	P-Value
Waist circumference (WC)	Underweight	3 (7.3%)	1 (0.9%)	4 (2.67%)	<0.001
	Normal BMI	161 (44.7%)	39 (6.7%)	200 (21.2%)	<0.001
	Overweight	306 (92.2%)	134 (74.9%)	440 (86.1%)	<0.001
	Obesity	347 (99.7%)	51 (98.1%)	398 (99.5%)	0.115
	Total	817 (75.6%)	225 (24.4%)	1042 (52.0%)
Waist-to-hip-ratio (WHR)	Underweight	15 (36.6%)	14 (12.8%)	29 (19.3%)	<0.001
	Normal BMI	182 (50.6%)	177 (30.4%)	359 (38.1%)	<0.001
	Overweight	233 (70.2%)	130 (72.6%)	363 (71.0%)	0.539
	Obesity	274 (78.7%)	47 (90.4%)	321 (80.3%)	0.010
	Total	704 (65.1%)	368 (39.9%)	1072 (53.5%)
Visceral Fat thickness (VFT)	Underweight	3 (7.3%)	4 (3.7%)	7 (4.7%)	0.208
	Normal BMI	74 (20.6%)	96 (16.5%)	170 (18.1%)	0.121
	Overweight	139 (41.9%)	62 (34.6%)	201 (39.3%)	0.081
	Obesity	228 (65.5%)	42 (80.8%)	270 (67.5%)	0.021
	Total	444 (41.1%)	204 (22.1%)	648 (32.4%)
Subcutaneous Fat thickness (SCFT)	Underweight	2 (4.8%)	1 (0.9%)	3 (2.0%)	0.021
	Normal BMI	143 (39.7%)	79 (13.6%)	222 (23.6%)	<0.001
	Overweight	281 (84.6%)	107 (59.8%)	388 (75.9%)	<0.001
	Obesity	339 (97.4%)	33 (66.0%)	372 (93.5%)	<0.001
	Total	765 (70.8%)	220 (23.9%)	985 (49.2%)

n = number of people with central obesity by BMI categories and gender, % is the percent with central obesity by gender and BMI status, p-values = are from chi-square test of association between central obesity and gender within each BMI category.

Table 5. Predictors of normal-weight central obesity as measured by WC and WHR.

	WC			WHR
	OR	95% CI		OR	95% CI
Socio-demographic factors
Sex (ref = men)	4.93	3.28	7.41	0.92	0.71	1.18
Age (ref = 40–50 years)	1.48	1.08	2.03	1.53	1.21	1.95
Education (ref = no education)
Primary	0.84	0.51	1.39	1.05	0.66	1.65
Secondary	0.84	0.48	1.46	1.03	0.64	1.67
Tertiary	0.57	0.07	4.7	2.42	0.91	6.43
Ethnicity (ref = Kamba)
Kikuyu	1.19	0.76	1.86	0.68	0.49	0.94
Luhya	0.73	0.39	1.34	0.89	0.61	1.29
Luo	1.47	0.88	2.44	0.75	0.52	1.08
Others	2.57	1.49	4.43	0.98	0.63	1.52
Employment (Ref = self-employed)
Employed (Full-time)	2.1	1.23	3.57	0.92	0.62	1.36
Employed (Part-time)	1.63	0.6	4.42	1.03	0.46	2.27
Employed (Informal)	1.11	0.77	1.6	1.29	0.98	1.7
Unemployed	0.77	0.4	1.46	1.21	0.74	1.97
Behavioral factors
Current use of alcohol	0.64	0.22	1.82	1.14	0.69	1.88
Currently smoking	1.08	0.39	3.01	1.43	0.86	2.35
At least 5 days fruit or veg	0.77	0.28	2.16	1.15	0.71	1.86
Work involves siting most of time	2.57	0.98	6.74	1.41	0.91	2.19

OR-Odds ratio, WC-Waist circumference, WHR-Waist to hip ratio, 95% CI – 95% confidence interval.