The protein nutritional value of an isolated soy protein (Supro-620) was evaluated in a series of nitrogen balance studies in healthy young male MIT students. Experiment 1 involved giving eight subjects graded intakes of the isolated soy protein while seven additional subjects received egg protein. Mean nitrogen intake required for N balance for the isolated soy protein and the egg protein were not significantly different (p greater than 0.1). In experiment 2, nine subjects received soy and the effects on N balance at various levels of L-methionine supplementation were studied. In experiment 3 eight subjects each were studied at two nitrogen intake levels of isolated soy protein/kg/day with methionine supplementation, and an unsupplemented egg protein period included. Results from experiment 2 and 3 at an 82 mg N/kg/day test level showed that N balance for 1.6% supplementation was significantly below that of unsupplemented egg while 1.1% and unsupplemented soy were indistinguishable from egg. No beneficial effects of methionine supplementation were observed when the test nitrogen intake level was 128 mg N/kg/day. These results indicate that for healthy adults, the isolated soy protein is of high nutritional quality, comparable to that of animal protein sources, and that the methionine content is not limiting for adult protein maintenance.

Obstructive sleep apnea (OSA) and the metabolic syndrome (MS) are independently associated with increased cardiovascular risk. The objective of the present study was to determine the prevalence of OSA among consecutive patients with MS and to determine whether OSA is associated with impaired glycemic control. Fifty consecutive patients with a recent diagnosis of MS and no previous diagnosis of OSA underwent a polysomnography and anthropometric and laboratory measurements. The prevalence of OSA (apnea-hypopnea index >or=15 events per hour of sleep) was 68% and in the same range of all other individual components of MS. Moreover, OSA was associated with increased levels of glucose (P=.03) and glycosylated hemoglobin (P=.03) but not with body mass index (P=.30). Glycosylated hemoglobin was independently associated with glucose (P<.001) and apnea-hypopnea index (P=.03). The prevalence of OSA is in the same range as all the individual components of MS and is independently associated with impaired glycemic control.

The protein nutritional value of an isolated soy protein was examined in healthy young men during 10-day N-balance periods. In the first study (expt 1), 10 young men received a diet providing a test protein (N X 6.25) intake of 0.6 g protein per kilogram per day with nitrogen from either lean beef, isolated soy protein or various combinations of the two sources. No differences in N balance, digestibility or net protein utilization were observed when the soy protein replaced beef. In the second study (expt 2), three separate groups of seven young men each received graded intakes of either beef or an isonitrogenous mixture of beef and the isolated soy protein or dried skim milk. An estimate was made of the N intake from each source required for N equilibrium. These values were 116, 106 and 103 mg N/kg per day, respectively. No statistically significant differences were found among the three dietary groups. Thus, the protein quality of the isolated soy protein appears to be comparable to that of animal protein sources such as milk and beef.

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Respiratory-dependent dynamic parameters for predicting fluid responsiveness in ICU may have restricted applicability in daily practice, even in more severe patients, due to low prevalence of required conditions.