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Background & objectives: Weight loss and hypernatremic dehydration is a common problem in infants with inadequate nutrition. Determination of risk factors and clinical characteristics of these neonates may help to prevent or early detection of hypernatremia. This study designed to determine the prevalence of clinical signs and risk factors for hypernatremic dehydration.

Methods: This study is a sectional descriptive study that conducted on 418 newborns during 1385 to 1393 AHS that referred to Ghaem hospital in Mashhad. The hypernatremic group consisted of 197 neonates with serum sodium level higher than 150 mg/dl and 221 isonatremic newborns with sodium level less than 150 mmol/L were included as controls. Both groups were compared in terms of clinical symptoms of dehydration and maternal risk factors. All data were recorded and coded. Data analysis performed using paired T test and chi square tests by SPSS 16 software.

Results: In the present study, 2.8% of infants were hypernatremic. The most common symptoms were neonatal jaundice (62.2%), hyperthermia (25.8%), lethargy (23.6%), agitation (20.8 %) and mucous membranes dryness (17.2%). Problems in pregnancy (p=0.002), inappropriate feeding techniques (p=0.000), the first lactation duration (p=0.022) and frequency per day (p=0.000) had statistically significant difference between case and control groups.

Conclusion: Prevalence of hypernatremic dehydrationis considerable in our study and identifying the risk factors may help to reduce its incidence or exacerbation. Weight loss, especially in newborns having jaundice, hyperthermia and irritability, may be helpful in the early diagnosis of hypernatremic dehydration

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Background & objectives: Caffeine can affect many physiological functions of the body. The aim of this study was to investigate the response of aerobic function, blood pressure and some immune system factors of trained men to acute caffeine consumption in dehydrated condition and warm and humid environment.
Methods: Thirty male athletes with a mean age of 26.6±3.9 years in dehydrated conditions voluntarily participated in this study, which was performed in a double-blind manner. Subjects were divided into three groups: caffeine consumption group (n=10), placebo group (n=10) and control group (n=10). The Caffeine group consumed 6 mg/kg body weight of caffeine. Sixty minutes later, the subjects performed an increasingly exhausting exercise. Blood samples collecting and blood pressure measuring took place before, immediately after and 24 hours after exercise. Analysis of variance with repeated measures (group * time) and one-way analysis of variance were used for statistical calculations.
Results: The duration of the exhaustion test in the caffeine consumption group was significantly longer than the control (p≤0.01) and placebo (p≤0.05) groups. In the blood sampling immediately after exercise, the level of leukocytes, neutrophils and lymphocytes in the exercise groups were significantly higher than the control group (p≤0.001). Also, the caffeine group experienced a lower increase in leukocytes and neutrophils compared to the placebo group (p≤0.001). Blood pressure values ​​in the exercise groups were significantly higher than the control group (p≤0.001). Also, the caffeine group experienced a greater increase in systolic blood pressure at baseline and immediately after exercise compared to the placebo group (p≤0.001).
Conclusion: In general, exhausting exercise in a warm environment and dehydrated condition increases the number of immune system cells and blood pressure. In addition to improving aerobic function, caffeine seems to prevent further increases in the number of immune system cells, while increasing blood pressure in the normal range in warm and humid environment.