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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #77469
Title: INSUFFICIENT DIETARY ENERGY INTAKE, BUT NOT INCREASED ENERGY EXPENDITURE, CONTRIBUTES TO GROWTH FAILURE IN GIRLS WITH RETT SYNDROME

Author
item Motil, Kathleen
item SCHULTZ, REBECCA - BAYLOR COLL OF MEDICINE
item WONG, WILLIAM - BAYLOR COLL OF MEDICINE
item GLAZE, DANIEL - BAYLOR COLL OF MEDICINE

Submitted to: Journal of Pediatrics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Rett Syndrome (RS) is a disabling developmental disease that strikes only females. RS girls stop growing normally, develop mental retardation, and display repetitive, involuntary movements involving the hands, feet, and body. We wanted to know whether these girls have increased energy output because of their involuntary movements. We studied a group of RS and normal lgirls over 10 days to observe their actions and the food they typically ate, and we measured their energy expenditure using the doubly labeled water technique. We found that when we adjusted for the fact the RS girls had far less lean body mass, their energy expenditure was not significantly different from healthy girls. The RS girls (who often have problems chewing and swallowing) ate one-fourth less than the healthy girls, which was the major factor contributing to their altered energy balance, and most likely led to their growth failure. Taking action early in life to ensure that RS girls eat better might reverse their growth failure and body composition problems.

Technical Abstract: Objective: To determine whether increased total daily energy expenditure (TDEE) due to repetitive, involuntary movements, as well as insufficient dietary energy intake, contribute to growth failure in girls with Rett syndrome (RS). Study design: Fourteen RS and 11 healthy girls were studied for 10 days to obtain measurements of height, weight, body circumference, and skinfold thickness using stadiometric and anthropometric methods; whol body potassium by 40K counting; 72-hour dietary energy intakes by test-weighing; 24-hour activity patterns using observational methods; and TDEE using the doubly labeled water technique. Results: TDEE, when adjusted for differences in lean body mass, did not differ significantly between RS and healthy girls. Although RS girls spent more waking hours in physical activity than their healthy counterparts (85 +/- 10 vs. 73 +/- 11% awake time/d, p<0.05), their repetitive movements were not sufficiently intense to increase TDEE. However, the RS girls had significantly less lean body mass, but not body fat, which contributed to a lower absolute TDEE than the healthy girls (845 +/- 251 vs. 1453 +/- 534 kcal/d, p<0.01). Dietary energy intake was significantly lower by 26% in RS than in healthy girls (1220 +/- 252 vs. 1657 +/- 445 kcal/d, p<0.01). Conclusions: Insufficient dietary energy intake, rather than higher TDEE due to repetitive, involuntary movements, was the major contributing factor to the altered energy balance and subsequent growth failure of RS girls. This observation suggests that early, aggressive nutritional intervention should reverse the abnormalities of growth and body composition of RS girls.