Association of B12 deficiency and anemia synergistically increases the risk of high TNF-α levels among adolescent girls

We investigated the association between iron status, B12, and inflammatory markers among 101 adolescent girls. We found that B12 showed significant negative association with tumor necrosis factor-alpha (TNF-α) (rs = -0.232, P = 0.020) and positive association with serum ferritin (SF) (rs = 0.209, P = 0.036) among girls. Our results showed that hepcidin discriminates anemic and non-anemic population under normal B12 conditions. The logistic regression analysis revealed that the risk of having higher TNF-α levels was 13.2 times higher in low B12 girls in the presence of anemia compared to the girls having normal hemoglobin and B12 levels.

Energy costs of standard activities among Indian adults

OBJECTIVES

To estimate the energy cost of resting (RMR), sitting and standing for urban Indian adults and compare these estimates with the reported values.

DESIGN

Energy costs were measured using oxylog while body fat was estimated using equipment (HBF300, OMRON Corporation, Japan) that works on the principle of bioelectrical impedance, for 24 men and 40 women, aged 20-50 y, engaged in sedentary activities.

SETTINGS

Agharkar Research Institute, Pune, India.

RESULTS

Mean energy cost (kJ/min) of resting (RMR), sitting and standing were significantly (P<0.01, for all) higher for men (4.01+/-0.42, 5.0+/-0.72 and 5.74+/-0.69, respectively) than women (3.54+/-0.28, 4.03+/-0.41 and 4.35+/-0.52, respectively). Gender difference increased with the level of activity, from 13% for RMR to 32% for standing. These differences reduced when adjusted (using analysis of covariance) for body weight and became non-significant on adjusting for fat-free mass (FFM) in the case of RMR and sitting activity. The measured values of energy cost (absolute and per kg weight) for these activities were similar to African subjects but lower compared to Asian or European subjects for both sexes. The stepwise regression analysis done separately by sexes showed weight (29%) in men and body mass index (44%) in women to be the best predictors of RMR, while regression analysis for combined sexes indicated FFM and height as predictors of RMR (r(2)=56%, P<0.01). If means to estimate body fat were not available, RMR could best be predicted with BMI and sex as predictors (r(2)=55%; P<0.01). This was mainly due to the fact that the sex differences in our population were more prominent in FFM than that in BMI. Our observations thus indicate the need to develop prediction equations separately for different populations owing to differences in their body compositions, especially in fat mass (FM) or FFM.

CONCLUSION

The energy costs of activities were associated with body composition, especially with absolute fat-free mass, which may vary even with the same body fat percentage. Therefore, there is a need to develop separate prediction equations for different communities.

Assessment of pearl millet vs rice based diets for bioavailability of four trace metals

Cereals including millets are consumed in India as a staple with wide variety of pulses and vegetables in varying proportions. Trace mineral contents of pearl millet are two to ten times higher than that of rice. Comparative performance of pearl millet based (PM) diets as against rice based (RB) diets in terms of trace mineral bioavailability was studied, based on the prevailing dietary patterns in India. In vitro percent dialysability of zinc, iron, copper and manganese under simulated gastrointestinal conditions was considered as indicator of metal bioavailability. Dialysable zinc and iron were estimated using 65 Zn and 59 Fe as tracers, while dialysable copper and manganese were measured by Atomic absorption spectrophotometer for 20 food items and 15 RB and 17 PM diets prepared from these items. Results indicated that percent dialysability of zinc and copper was higher for RB diets than PM diets, while that of iron and manganese were comparable. Total dialysable iron, copper and manganese in PM diet was 2 to 4 times higher than RB diet.

Zinc, copper & iron contents in cooked foods & estimates of their daily intakes in young hostel residents

Dietary zinc, copper and iron intakes of 19 men and 11 women (aged 18-25 yr) were determined during three periods of five consecutive days each, using, weighment method and atomic absorption analysis of food samples. Daily zinc, copper and iron intakes of men ranged from 13.1 +/- 1.2 to 15.3 +/- 1.4 mg/d, 1.62 +/- 0.15 to 1.84 +/- 0.17 mg/d and 20.5 +/- 2.8 to 29.1 +/- 4.5 mg/d and of women 8.8 +/- 2.0 to 9.0 +/- 1.6, 1.42 +/- 0.23 to 1.69 +/- 0.62, and 10.0 +/- 2.4 to 14.7 +/- 2.6 mg/d respectively. Cereals provided 67.7 per cent of dietary zinc, 47.7 per cent copper and 62 per cent iron in men and 60 per cent of Zn, 44 per cent of Cu and 59 per cent of Fe in women, suggesting lower contribution of cereals to Cu intakes than Zn and Fe. Men had mineral intakes close to the recommended allowances for Indians, whereas the intakes of women were 30 to 60 per cent lower. When expressed as mg/1000 kcal, lower calorie intakes of women were responsible for their low mineral intakes. Intra-individual variation in mineral intakes was higher (18.39%) than that of energy intakes (14-17%) in both men and women. Phytate: Zn molar ratios were > 15 indicating risk of zinc deficiency in these students.

Energy intake & resting metabolic rate of young Indian men & women

Energy intake, body weight and resting metabolic rate (RMR) were measured on seven days consecutively, in 20 men and 14 women on ad libitum food intake under free-living conditions. These measurements were repeated in 8 men and 9 women twice with an interval of two months. Mean energy intake (EI) as measured by 'Weightment' method, was 2820 +/- 577 kcal/d in men and 1611 +/- 147 kcal/d in women. EI showed significant differences between weeks (P less than 0.01, CV = 13.1% in men and 9.5% in women) and between subjects (P less than 0.05, CV = 13.7% in men and 9.8% in women). Intra individual variance contributed up to 60 to 70 per cent of the total variance in EI in both the groups. RMR measured by using Oxylog, varied between the three periods (CV = 6% in men and 5.9% in women) and between subjects (CV = 5.7% in men and 12.3% in women). Mean RMR of both men and women was lower than the predicted value by FAO/WHO/UNU equation. Estimate of mean 24 h energy expenditure, using activity diary and factorial method, in the first round was 2458 +/- 144 kcal in men and 1655 +/- 172 in women, resulting in an energy balance of 308 kcal in men and -44 kcal/d in women. The pattern of activity remained the same in the three rounds for both groups. There were no significant changes in weight (CV-1.6%) or per cent body fat during the study period (P greater than 0.1).