Ethnotribal Growth Differences among Schoolchildren in a Northwestern Maharashtra District: An Analytical Cross-Sectional Study.

CONTEXT: In Ashram schools, scheduled tribes (ST) children from age 6 to 17 years belonging to various ethnic groups stay under common living and dietary provisions. However, there are scant reports on ethnotribal height differences. AIMS: The aims of the study are to (a) estimate height differences between schoolchildren of three major local STs, (b) compare heights and average skinfold thickness (SFT) of ST with non-ST and urban schoolchildren, and (c) compare median heights and weights of ST and non-ST schoolchildren with the Indian Academy of Pediatrics standards. SETTINGS AND
DESIGN: Four Ashram schools and one urban school in Northwest Maharashtra. SUBJECTS AND METHODS: All children from age 6 to 17 years were included for height, weight, and mid-arm circumference (n = 2106). Data were processed with Excel and Epi info software for quantitative comparisons. STATISTICAL ANALYSIS USED: Quantitative methods including ANOVA were used for statistical comparison of heights.
RESULTS: There were no differences among heights between ST students (ANOVA P > 0.05). However, there were significant differences between heights of boys and girls between ST and non-ST students across age groups (ANOVA P < 0.0001). ST boys and girls were mostly below 3rd or 10th percentile of IAP height and weight charts while non-ST children were between 25th and 50th percentiles. The average SFT values for prepubertal age groups were significantly lower in ST schoolchildren.
CONCLUSIONS: ST students showed a significant growth disadvantage against general and other backward classes categories, although no intertribal anthropometry differences were observed. Copyright:

INTRODUCTION

The interest in growth profiles of ethnotribal communities started from the early last century in many colonized countries.[12345]

The phrase “scheduled tribes (ST)” is used in India for affirmative action. Some STs are “Particularly Disadvantaged Tribes Group (PVTGs).[67] This study uses the phrase ST in sociolegal sense based on constitution of India.[6] STs are the most disadvantaged sections in India by several socioeconomic indicators.[58] The National Family Health Survey 4 and Integrated Child Development System (ICDS) data of state of Maharashtra show the high malnutrition prevalence in under five (U5) children in tribal blocks.[910] However, there is not much information available for school populations, despite the Rashtriya Bal Swasthya Karyakram.[11]

Height of adults is a major parameter for growth differences. Childhood stunting suggests chronic malnutrition reflecting socioeconomic backwardness. On the contrary, weight for age, body mass index, Mid-upper arm circumference, and skinfold thickness (SFT) are rapid responders for better nutrition.[12]

This study was part of a larger study of food intakes and growth of schoolchildren in four tribal Ashram schools and an urban school for comparison. Ashram schools, apart from free formal education, provide accommodation, food, and health care for children of age groups 6–16 years for nearly 300 days/annum.[13] The Ashram school environment, therefore, is expected to “neutralize” any socioeconomic differences between various ethnic groups (STs) through common living conditions and food services.[14] If there are any ethnogenetic or racial differences between heights of STs, the children living for years under common conditions should show differences in growth trajectories.

The objectives of this study are to (a) compare heights of schoolchildren of three major local STs, (b) estimate the gap between heights of ST with non-ST urban schoolchildren, (c) compare heights and weights of schoolchildren with Indian Academy of Pediatrics (IAP) reference values, and (d) compare the average SFT between ST and non-ST children as an additional nutritional parameter.

SUBJECTS AND METHODS

Sampling

The selection of Ashram schools was done by random two-stage sampling. Of the six tribal blocks in the Nashik district in Northwest Maharashtra, four (Trimbak, Peth, Dindori, and Igatpuri) were randomly selected. In the second stage, schools were randomly selected from the pooled lists of Private and Government Ashram schools in the four blocks. For comparative anthropometry, an urban school from Nashik city was included.

The sample size was calculated for the main criterion of the prevalence of “stunting” as 38 from a research study conducted in Ashram schools for tribal children, in Nashik and Palghar Districts.[15] The formula used was, sample size n = (DEFF*Np [1-p)]/[d2/Z21-α/2*[N-1]+p*[1-p]).[16] Allowable error was 5% (33-43); cluster effect and correction for absentees were taken as 1.1% and 10%, respectively. The estimated sample size was 397 + 5% (say 420) in each Ashram school, hence 1680 in four Ashram schools.

A total of 2106 students from 6 to 17 years were included. Out of these, 86.6% were from ST categories. The data collection was completed from November 2017 to February 2018. All children present in Ashram schools on the day of examination were included.

Ethical consent and assent

IEC consent was obtained for the study. Permissions were sought from the tribal commissioner for government schools and the governing trusts for private schools. Assent of students was obtained before study in each school at the time of morning school prayers.

Anthropometry

Standing height was taken with a stadiometer (Height 200 cm. No. 26 SM) fixed on wall ensuring the head, toes, buttocks, and shoulders touching the wall.

Bodyweight was recorded, (using adult nondigital bathroom scale Model number – Ideal Industries, Pune) with usual school clothes but without footwear and belt. Measurement of boys and girls were done by a male and female researcher separately. The weighing scale did not show variation once adjusted for plane with spirit level. It was tested each day against a premeasured weight of sandbag wrapped in plastic. It did not show error of >0.1 kg any day. The nearest ½ kg weight was recorded.

SFT was measured with a handheld caliper, checked against a standard engineering ruler for 1 cm and 1 mm markings up to 70 mm. SFT was measured after removing upper clothes in privacy. Male and female medical researchers checked boys and girls, respectively, in separate rooms. The four SFT sites included subscapular, suprailiac (horizontal skinfold), and triceps and biceps (vertical skinfold), together making eight sites on both sides. An average of the total eight sites for SFT was calculated.

Data analysis

Data analysis was done with Excel. Epi info 7 Division of Health Informatics & Surveillance (DHIS), Center for Surveillance, Epidemiology & Laboratory Services (CSELS), USA.1 was used for frequency tables, age estimates, and height-weight and SFT comparisons.

Statistics

Quantitative methods including ANOVA were used for statistical comparison of heights.

RESULTS

Total participants were 2106. Out of these, 52.7% were girls (6.7% non-ST and 46% ST) and 47.2% boys (6.6% non-ST and 40.6% ST).

Urban-tribal differences in heights

It is seen from Tables 1 and 2 that ANOVA for caste and tribes for both ST boys and girls had statistically highly significant differences. The table also shows that both ST boys and girls had lower heights than non-ST/urban boys and girls in all age groups.

Table 1

Comparison of mean heights of boys in different sets of categories

Mean heights of boys in different sets of categories							Statistic
Age in years (n)	Statistic	Caste and tribe
		Non-ST		ST			Non-ST + ST		ST
		Gen and OBC	Miscellaneous	Kokna	Mahadev Koli	Varali	f-statistic	ANOVA (P)	f-statistic	ANOVA (P)
7,8,9 (251)	n	51	12	73	57	58	11.03	0.0000**	1.18	0.3105
	Mean	121.8	119.76	115.63	113.79	114.42
	SD	7.7	7.72	8.03	6.13	6.42
10, 11, 12 (279)	n	43	13	106	55	62	13.91	0.0000**	0.77	0.4624
	Mean	138.33	137.99	130.41	128.96	130.2
	SD	9.18	7.22	6.69	6.32	8.5
13, 14, 15 (285)	n	39	10	135	53	48	14.85	0.0000**	4.64	0.0106**
	Mean	158.45	156.56	146.24	150.97	146.23
	SD	8.89	7.61	10.16	9.06	10.32
16, 17 (181)	n	7	29	83	33	29	2.22	0.0000**	0.25	0.783
	Mean	164.01	160.44	158.2	157.68	158.79
	SD	6.29	5.8	7.19	4.78	4.57
Sub totals		140	64	397	198	197

**Denote highly significant (< 0.01). SD: Standard deviation, ST: Schedule tribes

Table 2

Comparison of mean heights of girls in different sets of categories

Mean heights of girls in different sets of categories							Statistic
Age I years (n)	Statistic	Caste and tribe					Non-ST + ST		ST
		Non-ST		ST
		Gen and OBC	Other ST	Kokna	Mahadev Koli	Varali	f-statistic	ANOVA (P)	f-statistic	ANOVA (P)
7, 8, 9 (223)	n	44	17	84	42	36	6.34	0.0001**	0.09	0.9103
	Mean	120.90	116.2	115.20	115.59	114.99
	SD	6.73	9.46	6.37	6.10	6.00
10, 11, 12 (319)	n	45	9	140	58	67	10.44	0.0000**	1.75	0.1750
	Mean	137.49	136.2	129.0	131.32	130.31
	SD	7.81	9.76	8.25	7.50	7.92
13, 14, 15 (356)	n	48	12	175	64	57	12.65	0.0000**	1.88	0.1530
	Mean	151.85	147.6	144.85	146.13	143.81
	SD	6.65	5.23	6.61	7.08	5.98
16, 17 (212)	n	5	20	123	35	29	2.04	0.0905	0.68	0.5079
	Mean	152.9	151.83	149.47	148.28	149
	SD	2.27	3.67	5.76	4.96	4.52
Sub totals		142	58	522	199	189

** Denote highly significant (< 0.01). SD: Standard deviation, ST: Schedule tribes

Analysis showed that the maximum height differences in boys between ST and non-ST were about 8, 10, 12, and 6 cm in successive age groups. Similarly, the maximum height differences in girls between ST and non-ST categories were about 6, 8, 8, and 4 cm in successive age groups.

The intertribal differences in heights among three STs (Kokna, Mahadev Koli, and Varali) for both boys and girls had no significant differences in any age group as seen from ANOVA results, except for boys of age group 13–15, wherein Mahadev Koli boys had a 4 cm edge over other two ST boys. Barring this, all growth trajectories coincided.

Comparison with Indian Academy of Pediatrics standards

Table 3 shows heights and weights of boys and girls of ST and non-ST (general and other backward classes) categories in terms of percentiles as per the IAP charts.[17]

Table 3

Age-wise median heights and weights in different categories compared to IAP reference values

Heights percentiles IAP					Weights percentiles IAP
Age (years)	Boys		Girls		Boys		Girls
	ST	Non-ST	ST	Non-ST	ST	Non-ST	ST	Non-ST
7	3rd-10th	10th-25th	3rd-10th	10-25th	3rd	10th-25th	3rd-10th	10th-25th
8	<3rd	10th-25th	10-25th	10-25th	<3rd	10th-25th	<3rd	10th-25th
9	<3rd	10th-25th	3rd-10th	10th-25th	<3rd	10th-25th	<3rd	3rd-10th
10	3rd-10th	10th-25th	3rd-10th	10th-25th	3rd-10th	25th-50th	<3rd	10th-25th
11	3rd-10th	25th-50th	<3rd	10th-25th	3rd-10th	10th-25th	<3rd	10th-25th
12	3rd-10th	10th-25th	3rd-10th	10th-25th	3rd-10th	10th-25th	<3rd	25th-50th
13	3rd-10th	25th-50th	3rd-10th	25th-50th	3rd-10th	25th-50th	3rd-10th	10th-25th
14	3rd-10th	25th-50th	3rd-10th	10th-25th	3rd-10th	10th-25th	3rd-10th	3rd-10th
15	10th-25th	50th-75th	10th-25th	25th-50th	3rd-10th	10th-25th	3rd-10th	25th-50th
16	10th-25th	10th-25th	10th-25th	10th-25th	3rd-10th	10th-25th	3rd-10th	10th-25th
17	3rd-10th	3rd-10th	10th-25th	10th-25th	3rd-10th	3rd-10th	3rd-10th	3rd-10th

IAP:Indian Association of Pediatrics, SD: Standard deviation, ST: Schedule tribes

It was observed that median heights in girls and boys were lower when compared with IAP standards. When ST and non-ST categories were compared, ST categories were found more stunted as compared to non-ST categories. Heights of ST boys and girls were around 3rd percentile or in the range of 3rd–10th percentile till prepubertal phase. After puberty, heights increased to 10th–25th percentile. Weights of ST children were either lower than 3rd percentile or in the range of 3rd–10th percentile, showing very poor weight gains.

On the contrary, heights and weights of non-ST children ranged from 10th to 25th percentile throughout all ages, with occasional rise to 25th–50th or even 50th–75th percentile.

Skinfold thickness

Table 4 shows the average SFT values on a 20% subsample. These were calculated from the total of eight sites. They were clubbed separately for ages 7–12 (prepubertal) and 13–16 years (postpubertal). The average SFT values for prepubertal age groups were significantly lower in ST boys and girls as compared to non-ST schoolchildren.

Table 4

Average skinfold thickness in schedule tribes and non-schedule tribes schoolchildren

Age (years)	Caste	Girls				Boys
		n	Mean	SD	P	n	Mean	SD	P
7-12	ST	109	6.03	1.5178	0.0037**	101	5.7661	1.5783	0.0088**
	Non-ST	23	7.92	2.7308		20	8.075	3.4963
13-16	ST	98	8.3559	2.0574	0.4141 (NS)	81	7.0617	2.5297	0.2961 (NS)
	Non-ST	14	9.3571	4.374		10	9.65	7.3581

** denote highly significant (< 0.01), NS: Not significant, SD: Standard deviation, ST: Scheduled tribes

DISCUSSION

India has about 8% ST population and Maharashtra's population has about 10% share of STs.[5] The ST communities in India are joining the mainstream society, but the STs are predominantly in lowest income quintiles of the Indian population, and consequently, experience malnutrition and mortalities.[58] This study covers three of the five tribes listed in Nashik but are not PVTGs.[718]

There are various schemes for development of STs in addition to general schemes such as ICDS, and Public Distribution System (PDS). Ashram schools are a special institution for supporting free education through residential schools.[13]

All three tribes currently live in common localities. Rice and Ragi are staples grown in Kharif season. Wheat was introduced in PDS for the last 20 years.[19] After Kharip season, most ST families migrate for employment in cities or agro farms in the district. Thus, these communities are still on subsistence level and also hugely benefit from the residential Ashram schools, where they can leave their children for year long.

One of the Ashram schools in the study belongs to preindependence era, and the others were established after 1980 after the Government scheme.[1320]

In an unpublished article by the authors about food intakes in the same Ashram schools, it was observed that average protein and calorie intakes across age groups were 84 g/student and 2300 kcal/student, respectively, and can be considered adequate by the National Institute of Nutrition standards.[21] These schoolchildren had no domestic, farm, or forest labor to do unlike day scholars. The conditions of sanitation and water supply were nearly similar in all the studied Ashram schools. Deworming is done once a year since 2016.[22] Government schools are providing egg and milk from 2018, but food conditions before the study period were similar in the four schools for staples, pulses, and vegetables. Thus, all other conditions except ethnicity can be treated as equal for STs in this study sample.

Weight changes generally reflect short-term nutritional history, while stunting suggests a long-term malady. Table 3 shows that ST and non-ST height weight differences are statistically significant; moreover, all ST schoolchildren in this study were stunted and underweight (3rd–10th percentiles), while there was some catch up to 10th percentile after pubertal age. Non-ST schoolchildren's heights and weights range between 25th and 50th percentiles of IAP growth charts. This could be due to socioeconomic gap between STs and non-STs. The notable fact of stunting, despite an earlier study by the authors reporting adequate protein and calorie intakes, could be due to the U5-stunting that was not being fully mitigated subsequently. Moreover, the lower values of weight for age in the study sample also suggested malnutrition. Hence, there exists a real nutrition gap or overall gap of living conditions (water sanitation, health care) between STs and non-STs. This is an issue to address.

On the other hand, the clustering of heights of all STs across age and gender suggest the absence of ethnogenetic differences in heights for the three STs. The STs have social segregation and intermarriage is scant. Thus, it could be said that ethnogenetic differences in heights could be negligible. Alternatively, the U5 stunting trajectory may have masked the full phenotypical expression of genetic height traits. The stunting problem is a general fact across all STs in the study population. The lack of between-ST height differences is convincing since the environment and food intakes are common to all ST children in the study population.

SFT is a measure of body fat stores. Table 4 shows that prepubertal ST boys and girls had significantly lower SFTs than non-ST schoolchildren. These findings suggest lower energy stores of ST schoolchildren, and these are consistent with lower heights and weights for age as compared to non-ST schoolchildren. Some authors recommend only triceps SFT instead of eight sites used in this study.[23] This was checked in this sample, and it was found that the left side triceps SFT showed high correlation with the pooled average SFT of eight sites, (0.69, P = 0.000).

This study implies that wholesome efforts are necessary to improve preschool and school-age heights and weights. Emphasis is necessary to improve protein quality and cereal-pulse proportion, and eggs and milk should fill this gap.

Limitations

The study has some limitations, especially because of small numbers in each age-gender-ST cell hampering closer comparison. The study was also limited to just three STs of one region.

CONCLUSIONS

This study establishes the following facts about growth of ST schoolchildren: (a) ST schoolchildren suffer a significant height and weight deficit as compared to non-ST/urban school children, (b) no significant differences of height/stunting existed between the three tribes, and (c) weight and SFT data suggest that ST children have low-energy reserves.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.