Original research: obesity prevalence and metabolic differences between obese and non-obese school adolescents in south-western Nigeria

Figures & data

Table 1: Socio-demographic characteristics of the respondents (n = 1 000)

Variable	n	%
Age group (years)^*
10–13  (early adolescence)	455	45.5
14–16  (mid adolescence)	460	46.0
17–19  (late adolescence)	85	8.5
Sex
Male	510	51.0
Female	490	49.0
Ethnicity
Yoruba	935	93.5
Other tribes	65	6.5
Father’s educational status
Low^**	175	17.5
High^***	651	65.1
Unknown	174	17.4
Mother’s educational status
Low^**	219	21.9
High^***	606	60.6
Unknown	175	17.5
Socio-economic status
Low	516	51.6
High	484	48.4
School type
Public	488	48.8
Private	512	51.2
Class
Junior secondary	573	57.3
Senior secondary	427	42.7

^* The mean age for the respondents was 13.73 years (standard deviation 2.04)

^** Low (without formal education or with an incomplete secondary education)

^*** High (completed secondary education or a tertiary education)

Table 2: Weight category and sex of the respondents (n = 1 000)^*

Sex	Weight category			n (%)
	Normal weight (%)n = 894	Overweight (%)n = 77	Obese (%)n = 29
Male	473 (92.7)	27 (5.3)	10 (2.0)	510 (100.0)
Female	421 (85.9)	50 (10.2)	19 (3.9)	490 (100.0)

^* Degrees of freedom = 2, χ² = 12.29, p = 0.002

Table 3: Comparison of the means for the waist circumference and blood pressure of the respondents by weight status using one-way analysis of variance

Variable	Weight category
	Normal weightn= 894	Overweightn = 77	Obesen = 29
Mean SBP (mmHg)^*	101.6 ± 13.2	113.1 ± 11.2	116.7 ± 15.1
Mean DBP (mmHg)^**	65.1 ± 9.6	72.6 ± 7.8	74.7 ± 12.1
Mean WC (cm)^***	67.5 ± 6.3	80.3 ± 6.4	88.5 ± 11.2

DBP: diastolic blood pressure, SBP: systolic blood pressure, WC: waist circumference

^* The F statistic and p for the mean systolic blood pressure is 44.40 and < 0.001, respectively

^** The F statistic and p for mean diastolic blood pressure is 33.85 and < 0.001, respectively

^*** The F statistic and p for the mean waist circumference is 268.88 and < 0.001, respectively

Table 4: A comparison of the means of some of the parameters in the obese respondents (n = 29) and the non-obese controls (n = 29) using an independent t-test

Parameter	Obese (n = 29)		Control (n = 29)		Statistic
	Mean	SD	Mean	SD	Mean difference	t-statistic	p
WC (cm)	88.5	11.2	67.8	6.3	−20.83	−8.75	< 0.001^*
SBP (mmHg)	116.7	15.0	100.2	14.6	−16.45	−4.23	< 0.001^*
DBP (mmHg)	74.7	12.1	65.4	8.8	−9.31	−3.75	0.001^*
HDL (mmol/l)	1.21	0.31	1.46	0.37	0.26	2.86	0.006^*
LDL (mmol/l)	2.30	0.73	1.98	0.61	−0.31	−1.79	0.079
Cholesterol (mmol/l)	4.00	0.63	3.95	0.67	−0.04	−0.26	0.790
Triglycerides (mmol/l)	1.07	0.35	0.94	0.21	−0.13	−1.74	0.090
FBG (mmol/l)	5.7	0.7	5.6	0.5	−0.12	−0.67	0.506

DBP: diastolic blood pressure, FBG: fasting blood glucose, HDL: high-density lipoprotein, LDL: low-density lipoprotein, SBP: systolic blood pressure, SD: standard deviation, WC: waist circumference

^* Statistically significant at p < 0.05.