2328 LETTERS TO THE EDITOR ccps skinfold thickness. However, the mid-ascaris infection and human nutrition is un- arm circumference remained unchanged, sig- certain. In a recent study (3), it was found nifying that the body muscle mass decreased; that 2 monthly piperazinc administration for this leads one to the impossible conclusion an year was not different from placebo as that antiascaris treatment-induced a state of regards effect on growth. It may be men- negative nitrogen balance. tioncd that in the recent international seminar 4) Authors did not monitor height along on “Control of parasites in prevention of with weight. There is evidence to suggest thatmalnutrition” (Tokyo, December 1-5, 1980), height is a better index of nutritional statusit was unanimously agreed that there is no than weight (2). In a recent longitudinal study clear cut evidence of a significant effect of in Guatemala (3), height was found to ascanasis be on nutrition and it was stressed that more sensitive than weight as a measure of further research in this area is needed. growth over a period of 1 yr. Mahesh C. Gupta, M.D. 5) Use of two of the indices (percentage weight for age and percentage expected Assistant Professor weight gain) might have been erratic in case Human Nutrition Unit of children aged 54 to 60 months at the onsetAll-India Institute of Medical Sciences of this 6-month study. This is because differ- Ansari Nagar, New Delhi up India 110029 Downloaded from www.ajcn.org by on June 3, 2010 ent standards were used for children to and more than 60 months of age. Thus the References % weight for age for a child aged 57 months initially would be determined from the Har- 1. Stephenson LS, Crompton DWT, Latham MC, yard standards at the onset of the study and Schulpen TWJ, Nesheim MC et al. Relationship from the Iowa standards at the end of the between Ascaris infection and growth of malnour- ished preschool children in Kenya AM J Clin Nutr study. Use of different scales to compare the l980;33:l 165-72. growth of the same child is liable to reduce 2. Mata L. The nature of nutrition problem. In: “Nu- the comparability of growth in different pe- trition Planning. The state of the Art”. L. Joy (ed). riods. IPC science and Technology Press Ltd., Surrey. Eng- land, 1978:91-9. 6) Authors found that growth changes were 3. Gupta MC, Urrutia iJ. Efecto del tratamiento qui- most marked in relation to skinfold thickness mioterapeutico periodico de parasitos intestinales, than in the case of the three criteria based on sobre el crecimiento de nifios preescolares. INCAP, body weight. This observation is certainly Guatemala: INCAP/UNU publication no 5, 1980. 4. Garn SM, Rosen NN, McCann MB. Relative values unusual for the following two reasons:a) of different fat folds in a nutritional survey. Am i Triceps skinfold is not a reliable indicator of Chin Nutr 197 1;24:1380-1. body fat stores (4, 5); also, various sources of Crook 5. GH, Bennett CA, Norwood D and Mahaffey error in measuring triceps skinfold arc well JA. Evaluation ofskinfold measurements and weight known (6). b) Tricpes skinfold remains rather chart to measure body fat. J Am Med Ass 1966;198: 39-44. constant, in the age group studied by the 6. Ruiz L, Colley JRT, Hamilton PJS. Measurement of authors (7) and its measurement is not rec- triceps skinfold thickness. An investigation of ommcndcd in the preschool children (8). sources of variation. Brit i Prey Soc Med 197 l;25: 7) Age and sex distribution in the control 165-67. and study groups are not given; one hopes 7. Jelliffe DB. The Assessment ofthe Nutritional Status of the Community. WHO. Monograph Series No. they were comparable. 53. Geneva: World Health Organization. 1966:227. Clarification of above points is important 8. ICNND. Manual for nutrition surveys. Washington, because the nature of interactions between DC: US Govt Printing Office 1963. Reply to letter by Gupta Dear Sir: We arc pleased to respond to Dr. Gupta’s nourished Kenyan preschool children (1). request for clarifications on our article con- 1) Dr. Gupta queries our statistical analy- cerning Ascaris infection and growth of mal-sis, our use of intergroup (rather than intra- LETTERS TO THE EDITOR 2329 group) comparisons, and our reference to changes in some other anthropometric mea- “seasonal factors” which may have caused sures. We did measure height at the begin- differences in growth rate in all subjects overning and the end of the study and reported time. We are interested to note that Dr. Gupta mean height/age and weight/height in our has now discovered the paired t test, since in article. There was simply no point in repeat- his own study, also concluding as we did that ing this measurement a mere 14 wk after the deworming can improve child growth (2), he first height measurement was made. used only ax2 test; whereas we used f tests, 3) We agree with Dr. Gupta that it was paired and unpaired t tests, analysis of vari- objectionable to have to use the Harvard ance, and multiple regression as required standards in for children up to 60 months of age different sections of the data analysis. and then switch to the Iowa standards. In We are aware that both groups of children 1976, those were the obvious choices. Fortu- grew better in the second than in the first nately we now have available the WHO! period. Dr. Gupta questions “seasonal fac- NCHS reference data (5, 6). It is not true tors” but in fact it is clear that seasonal however, that we used the Harvard standards differences in growth did occur in our entire for a 57-month-old child at the start of the sample of children. The weight gain in studyall but switched to the Iowa standards children (n = 291) was twice as large in the when he became over 60 months old. For Downloaded from www.ajcn.org by on June 3, 2010 second 14 wk of the study compared to the these children, the Harvard standards were first 14 wk (see Table 1). Less than 30% of extrapolated upwards assuming linear growth these children were Ascaris-infected, and in the few months past 60 months of age. only 187 participated in the Ascaris-study, This was a reasonable extrapolation and, in thus there was a seasonal variation in growth. any case, involved a very small percentage of However, in spite ofthat, the Ascaris-infected the sample. The fact that dewormed children children gained more weight and skinfold gained more weight in kilograms compared than uninfected ones in the second interval to controls makes the concern over standards after deworming. This analysis controls for irrelevant. seasonal differences in growth, which have 4) Dr. Gupta is concerned that the “age also been noted in other groups of East Al- and sex distribution in the control and study rican children (3, 4). We know of no pub- groups are not given; one hopes that they lished data to show that the small dose were of comparable.” We would hope that Dr. lcvamisole used for deworming could haveGupta would have carefully read our paper caused this profound seasonal difference before in writing his letter. In the first paragraph weight gain and we have addressed this point of our results section, we report the age and in our article (1). Our detailed analyses do sex distribution and also state that there were still lead to the conclusion that deworming no statistically significant associations found was related to improved growth. between the Ascans and control groups and 2) We do agree that height is a good indi- sex and age group using f a test (1). cator of chronic protein energy malnutrition, 5) Dr. Gupta objects to our use of triceps however it is not sensitive to short-term skinfold because it is “not a reliable indicator changes because the inherent measurement of body fat,” because it has “various sources error is similar to the actual height increase. of error,” because it “remains constant in the In longitudinal studies of short duration age group studied,” and because it is “not changes in height arc much less useful thanrecommended in preschool children.” a) Triceps skinfo!d is not a perfect indicator of body fat stores, but neither is the potas- TABLE 1 sium-40 method (7). Skinfold thickness is, Seasonal variation in children’s weight gain however, the only commonly used anthro- pomctric field technique that directly mea- Time intervals n Weight gain (kg/yr (5 ± SE)) sures a portion of body fat itself. 1st 14 wks 291 0.90 ± 0.10 Paired t test b) It does have “various sources of error,” (Dec-Mar) especially in the hands of untrained persons. 2nd 14 wks 291 2.15 ± 0.10 p < 0.0009 So does every other technique for assessment (Mar-June) of nutritional status. Need we say more? 2330 LETTERS TO THE EDITOR c) Triceps skinfold thickness does “remain” contributed to our belief that malnourished fairly “constant in the age group studied”f children grow better without worms. the children are equally well-nourished over Lani S. Stephenson time. The children in our study were not, partly due to seasonal variation and partly due to treatment for Ascaris infection. A ma-Visiting Assistant Professor rasmic child has a very low skinfold, and International an Nutrition obese child has a very high one; triceps skin-Division of Nutritional Sciences fold thickness is related to effective caloric Cornell University intake and to body energy stores. Ithaca, NY 14853 d) The fact that the ICNND manual (8) (1963, very useful but now out of print) does References not mandate that triceps skinfold thickness be measured in preschool children can hardly 1. Stephenson LS, Crompton DWT, Latham MC, be taken as proof that should it not be mca- Schulpen TWJ, Nesheim MC, iansen AAJ. Rela- sured in this age group. It has been used so tionships between Ascaris infection and growth of malnourished preschool children in Kenya. Am i many large scale surveys in the United States Chin Nutr 1980;33:1165-72. and elsewhere that we do not see any point 2. Gupta MC, Mithal S. Arara KL, Tandon BN. Effects Downloaded from www.ajcn.org by on June 3, 2010 in clarifying this further. of periodic deworming on nutritional status As- of 6) We cannot quickly obtain a copy of Dr. cans-infested preschool children receiving supple- mentary food. Lancet 1977;l:108-9. Gupta’s second study ofAscaris infection and 3. Robson iRK. Seasonal influence on height and growth (9) and so arc unable to comment on weight increments of boys and girls in Tanganyika. its design, statistical analysis, and results. i Trop Med Hyg 1964;67:46-9. 7) We fmd Dr. Gupta’s verbal report from 4. Longhurst R, Payne P. Seasonal aspects of nutrition: the recent international seminar on “Control review of evidence and policy implications. Discus- sion paper. Brighton, England: Institute for Devel- of Parasites in Prevention of Malnutrition” opment Studies, University of Sussex, November, (Tokyo, Japan, December, 1980) very inter- 1979. esting. Dr. Gupta reports that “it was unani- 5. World Health Organization. A growth chart for in- mously agreed that there was no clear cut ternational use in maternal and child health care: guidelines for primary health care personnel. Ge- evidence of asignificant effect of ascariasis neva: WHO, 1978. on nutrition (SIC).” However a recent report 6. National Center for Health Statistics. NCHS growth we obtained (10) states that “the assembled curves for children birth-l8 years. United States. agreed that the relationship between infection Hyattsville, MD: National Center for Health Statis- with soil-transmitted hclminths and nutrition tics, 1977. (Vital and health statistics. ser. 11: Data from the national health survey. no. 165) (DHEW dcfmitcly exists but the extent of its contri- publ. no. (PHS)78-1650.) bution to the general problem is not well7. Dugdale AL, Griffiths M. Estimating body mass fat understood.” For nearly 30 yr numerous iso- from anthropometric data. Am J Chin Nutr 1979;32: lated, mainly clinical, studies have appeared 2400-3. 8. ICNND. Manual for nutrition surveys. Washington, to prove that Ascaris infection and malnutri- US Government Printing Office, 1963. tion are related. Our study was an attempt to Gupta 9. MC, Urrutia ii. Efecto del tratamiento qui- quantfy the relationship between Ascaris in- mio-terapeutico periodico de parasitos intestinales, fection and malnutrition in a rural African sobre el crecimiento de niiios preescolares. INCAP, community. We agree wholeheartedly with Guatemala: INCAP/UNU publ. no. 5, 1980. 10. Experts, administrators affirm parasite-nutrition link Dr. Gupta that “further research in this area at Tokyo seminar. JOICFP News (newspaper of the is needed.” However we also feel that our Japanese organization for international co-operation study in Kenya, and his work in India, have in family planning) no. 79 Jan 198l:3(ool 1).
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