ABSTRACT
Maximal oxygen uptake (VO2max) during a graded maximal exercise test is the objective method to assess cardiorespiratory fitness. Maximal oxygen uptake testing is limited to only a few laboratories as it requires trained personnel and strenuous effort by the subject. At the population level, submaximal tests have been developed to derive VO2max indirectly based on heart rate based nomograms or it can be calculated using anthropometric measures. These heart rate based predicted standards have been developed for western population and are used routinely to predict VO2max in Indian population. In the present study VO2max was directly measured by maximal exercise test using a bicycle ergometer and was compared with VO2max derived by recovery heart rate in Queen’s College step test (QCST) (PVO2max I) and with VO2max derived from Wasserman equation based on anthropometric parameters and age (PVO2max II) in a well defined age group of healthy male adults from New Delhi. The values of directly measured VO2max showed no significant correlation either with the estimated VO2max with QCST or with VO2max predicted by Wasserman equation. Bland and Altman method of approach for limit of agreement between VO2max and PVO2max I or PVO2max II revealed that the limits of agreement between directly measured VO2max and PVO2max I or PVO2max II was large indicating inapplicability of prediction equations of western population in the population under study. Thus it is evident that there is an urgent need to develop nomogram for Indian population, may be even for different ethnic sub-population in the country.
ABSTRACT
Chyawanprash is an ancient Indian dietary supplement containing vitamin C (34 mg/100 g) derived from amla (Emblica officinalis). In addition, Chyawanprash also contains several other herbal products. The present study was designed to compare the effects of vitamin C with those of Chyawanprash. Ten normal healthy adult male volunteers (age 20-32 years) participated in the 16-week study. They were placed randomly in either the Chyawanprash group (n = 5) or vitamin C group (n = 5). Those in the former received 15 g/d of Chyawanprash while those in the latter received 500 mg/d vitamin C during the first 8 weeks of the study. For the next 8 weeks, no supplement was given. For each individual, an oral glucose tolerance test was performed, and lipoprotein profile in peripheral serum samples was determined at 0 weeks, 4 weeks, 8 weeks, 12 weeks and 16 weeks. In the Chyawanprash group, the 8 weeks Vs 0 weeks value (mean +/- S.D.) respectively for various indices which were significantly different were fasting plasma glucose (100.2 +/- 5.58 mg/dl vs 116.2 +/- 11.6 mg/dl), area under 2-h plasma glucose curve (245.9 +/- 15.13 mg.dl-1.h vs 280.8 +/- 37.09 mg.dl-1.h), HDL cholesterol (53.2 +/- 4.56 mg/dl vs 42.7 +/- 7.17 mg/dl), LDL cholesterol (82.4 +/- 8.80 mg/dl vs 98.26 +/- 12.07 mg/dl), LDL/HDL ratio (1.56 +/- 0.28 vs 2.38 +/- 0.63). In the Vitamin C group, only the LDL/HDL ratio was significantly lower at 8 weeks than at 0 weeks (1.99 +/- 0.44 vs 2.29 +/- 0.43). All the variables that changed significantly were no longer significantly different from the 0 weeks value at 16 weeks. Chyawanprash reduces postprandial glycemia in the oral glucose tolerance test and reduces blood cholesterol level to a significantly greater extent than vitamin C.