Endocrine responses to acute and chronic high-altitude exposure (4,300 meters): modulating effects of caloric restriction

2006 ◽  
Vol 290 (6) ◽  
pp. E1078-E1088 ◽  
Author(s):  
Kimberly E. Barnholt ◽  
Andrew R. Hoffman ◽  
Paul B. Rock ◽  
Stephen R. Muza ◽  
Charles S. Fulco ◽  
...  
Keyword(s):  
Body Weight ◽  
High Altitude ◽  
Sea Level ◽  
Caloric Restriction ◽  
Thyroid Stimulating Hormone ◽  
Normal Weight ◽  
Morning Cortisol ◽  
Maintain Body Weight ◽  
Baseline Values ◽  
The Difference

High-altitude anorexia leads to a hormonal response pattern modulated by both hypoxia and caloric restriction (CR). The purpose of this study was to compare altitude-induced neuroendocrine changes with or without energy imbalance and to explore how energy sufficiency alters the endocrine acclimatization process. Twenty-six normal-weight, young men were studied for 3 wk. One group [hypocaloric group (HYPO), n = 9] stayed at sea level and consumed 40% fewer calories than required to maintain body weight. Two other groups were deployed to 4,300 meters (Pikes Peak, CO), where one group (ADQ, n = 7) was adequately fed to maintain body weight and the other [deficient group (DEF), n = 10] had calories restricted as above. HYPO experienced a typical CR-induced reduction in many hormones such as insulin, testosterone, and leptin. At altitude, fasting glucose, insulin, and epinephrine exhibited a muted rise in DEF compared with ADQ. Free thyroxine, thyroid-stimulating hormone, and norepinephrine showed similar patterns between the two altitude groups. Morning cortisol initially rose higher in DEF than ADQ at 4,300 meters, but the difference disappeared by day 5. Testosterone increased in both altitude groups acutely but declined over time in DEF only. Adiponectin and leptin did not change significantly from sea level baseline values in either altitude group regardless of energy intake. These data suggest that hypoxia tends to increase blood hormone concentrations, but anorexia suppresses elements of the endocrine response. Such suppression results in the preservation of energy stores but may sacrifice the facilitation of oxygen delivery and the use of oxygen-efficient fuels.

Increased energy intake minimizes weight loss in men at high altitude

1992 ◽  
Vol 72 (5) ◽  
pp. 1741-1748 ◽  
Author(s):  
G. E. Butterfield ◽  
J. Gates ◽  
S. Fleming ◽  
G. A. Brooks ◽  
J. R. Sutton ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
High Altitude ◽  
Sea Level ◽  
Energy Intake ◽  
Nitrogen Balance ◽  
Volatile Fatty Acids ◽  
Energy Requirement ◽  
Fecal Excretion ◽  
Maintain Body Weight

The hypothesis that high-altitude weight loss can be prevented by increasing energy intake to meet energy requirement was tested in seven men, 23.7 +/- 4.3 (SD) yr, taken to 4,300 m for 21 days. Energy intake required to maintain body weight at sea level was found to be 3,118 +/- 300 kcal/day, as confirmed by nitrogen balance. Basal metabolic rate (BMR), determined by indirect calorimetry, increased 27% on day 2 at altitude and then decreased and reached a plateau at 17% above the sea level BMR by day 10. Energy expended during strenuous activities was 37% lower at altitude than at sea level. Fecal excretion of energy, nitrogen, total fiber, and total volatile fatty acids was not significantly affected by altitude. Energy intake at altitude was adjusted after 1 wk, on the basis of the increased BMR, to 3,452 +/- 452 kcal/day. Mean nitrogen balance at altitude was negative (-0.25 +/- 0.71 g/day) before energy intake was adjusted but rose significantly thereafter (0.20 +/- 0.71 and 0.44 +/- 0.66 g/day during weeks 2 and 3). Mean body weight decreased 2.1 +/- 1.0 kg over the 3 wk of the study, but the rate of weight loss was significantly diminished after the increase in energy intake (201 +/- 75 vs. 72 +/- 48 g/day). Individual regression lines drawn through 7-day segments of body weight showed that in four of seven subjects the slopes of body weight were not significantly different from zero after the 2nd wk. Thus weight loss ceased in four of seven men in whom increased BMR at altitude was compensated with increased energy intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrospinal fluid in man native to high altitude

1964 ◽  
Vol 19 (2) ◽  
pp. 319-321 ◽  
Author(s):  
J. W. Severinghaus ◽  
A. Carceleń B.
Keyword(s):  
Cerebrospinal Fluid ◽  
High Altitude ◽  
Sea Level ◽  
Regulation Of Respiration ◽  
Acid Base ◽  
Peripheral Chemoreceptor ◽  
Arterial Blood ◽  
Blood Ph ◽  
The Difference

CSF pH was shown in a prior report to remain essentially constant during 8 days of acclimatization to 3,800 m. In order to further evaluate the possible role of CSF acid-base equilibria in the regulation of respiration, 20 Peruvian Andean natives were studied at altitudes of 3,720–4,820 m. In ten subjects at 3,720 m, means were: CSF pH 7.327, Pco2 43, HCO3- 21.5, Na+ 136, K+ 2.6, Cl- 124, lactate 30 mg/100 ml. Arterial blood: pH 7.43, Pco2 32.5, HCO3- 21.3, Na+ 136, K+ 4.2, Cl- 107, hematocrit 49, SaOO2 89.6. In six subjects at 4,545 m and four at 4,820 m CSF values were not significantly different; mean arterial Pco2 was 32.6 and 32.3, respectively. The only significant variations with altitude were the expected lowering of PaOO2 to 47 and 43.5 mm Hg, and of SaOO2 to 84.2 and 80.7, and increase of hematocrit to 67% and 75%, respectively. The natives differed from recently acclimatized sea-level residents in showing less ventilation (higher Pco2) in response to the existing hypoxia, and less alkaline arterial blood. The difference appears to relate to peripheral chemoreceptor response to hypoxia rather than central medullary chemoreceptor. respiratory regulation at high altitude; chronic acclimatization to altitude; peripheral chemoreceptor response to hypoxia; CSF and medullary respiratory chemoreceptors Submitted on June 12, 1963

Abuse of Laxatives to Reduce Weight

1988 ◽  
Vol 9 (7) ◽  
pp. 208-234
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Anorexia Nervosa ◽  
Bulimia Nervosa ◽  
Diagnostic Criteria ◽  
Normal Weight ◽  
Intense Fear ◽  
Maintain Body Weight ◽  
Psychiatric Conditions ◽  
Weight For Age

Two psychiatric conditions are commonly associated with laxative and/or diuretic abuse to control weight. They are anorexia nervosa and bulimia nervosa. The newest diagnostic criteria for anorexia nervosa now makes it possible to diagnose this disorder before profound weight loss has occurred. There are four criteria: (1) refusal to maintain body weight greater than a minimum normal weight for age and height, the minimum being 15% below that expected; (2) intense fear of gaining weight; (3) a disturbance in the way one's body weight, size, or shape is experienced; and (4) amenorrhea in girls. Anorexia nervosa usually begins in early to late adolescence. It is primarily a disorder of girls.

Intestinal carbohydrate absorption and permeability at high altitude (5,730 m)

1994 ◽  
Vol 76 (5) ◽  
pp. 1903-1907 ◽  
Author(s):  
A. J. Dinmore ◽  
J. S. Edwards ◽  
I. S. Menzies ◽  
S. P. Travis
Keyword(s):  
Body Weight ◽  
High Altitude ◽  
Sea Level ◽  
Intestinal Permeability ◽  
Intestinal Function ◽  
Carbohydrate Absorption ◽  
Dietary Records ◽  
The Uk ◽  
Glucose Excretion ◽  
Paired T Test

To investigate the effects of high altitude on intestinal function, the absorption and permeation of nonmetabolizable carbohydrates were measured in 14 volunteers (median age 21 yr, range 19–37 yr) at sea level in Oxford, UK; at 1,050 m in Nepal; at 5,570 m after 5 days at > 5,500 m; and at 5,730 m after 11 days at > 5,500 m. Body weight decreased 5.7 +/- 1.19 kg from sea level to 5,570 m (P < 0.001 by paired t test) despite 72-h dietary records showing no change in energy intake. Absorption of carbohydrates by mediated transport was measured by urinary xylose and 3-O-methyl-D-glucose excretion. Xylose excretion (%oral dose) decreased from 31.4 +/- 4.5% to 20.7 +/- 4.5% (P < 0.001) and 3-O-methyl-D-glucose excretion decreased from 39.7 +/- 6.1 to 33.7 +/- 7.0% (P = 0.003) from sea level to 5,730 m. Monosaccharide permeation measured by L-rhamnose excretion decreased from 11.3 +/- 2.5 to 6.2 +/- 2.0% (P = 0.001). Intestinal permeability, a measure of barrier function (ratio of lactulose to L-rhamnose), increased from 0.036 +/- 0.014 at sea level to 0.084 +/- 0.042 at 1,050 m (P = 0.006), possibly due to infective enteropathy after arrival in Nepal, but reverted to normal (0.045 +/- 0.013; P = 0.062) at 5,730 m. Absorption of all carbohydrates returned to normal after return to the UK. This study showed that a decrease in mediated (D-xylose or 3-O-methyl-D-glucose) and diffusional (L-rhamnose) monosaccharide absorption occurs at high altitude but that intestinal permeability at 5,730 m is unchanged.

Skeletal muscle changes after endurance training at high altitude

1991 ◽  
Vol 71 (6) ◽  
pp. 2114-2121 ◽  
Author(s):  
A. X. Bigard ◽  
A. Brunet ◽  
C. Y. Guezennec ◽  
H. Monod
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Lactate Dehydrogenase ◽  
High Altitude ◽  
Endurance Training ◽  
Sea Level ◽  
Dehydrogenase Activity ◽  
Altitude Training ◽  
Lactate Dehydrogenase Activity ◽  
Simulated High Altitude

The effects of endurance training on the skeletal muscle of rats have been studied at sea level and simulated high altitude (4,000 m). Male Wistar rats were randomly assigned to one of four groups: exercise at sea level, exercise at simulated high altitude, sedentary at sea level, and sedentary at high altitude (n = 8 in each group). Training consisted of swimming for 1 h/day in water at 36 degrees C for 14 wk. Training and exposure to a high-altitude environment produced a decrease in body weight (P less than 0.001). There was a significant linear correlation between muscle mass and body weight in the animals of all groups (r = 0.89, P less than 0.001). High-altitude training enhanced the percentage of type IIa fibers in the extensor digitorum longus muscle (EDL, P less than 0.05) and deep portions of the plantaris muscle (dPLA, P less than 0.01). High-altitude training also increased the percentage of type IIab fibers in fast-twitch muscles. These muscles showed marked metabolic adaptations: training increased the activity levels of enzymes involved in the citric acid cycle (citrate synthase, CS) and the beta-oxidation of fatty acids (3 hydroxyacyl CoA dehydrogenase, HAD). This increase occurred mainly at high altitude (36 and 31% for HAD in EDL and PLA muscles; 24 and 31% for CS in EDL and PLA muscles). Training increased the activity of enzymes involved in glucose phosphorylation (hexokinase). High-altitude training decreased lactate dehydrogenase activity. Endurance training performed at high altitude and sea level increased the isozyme 1-to-total lactate dehydrogenase activity ratio to the same extent.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Perbandingan prevalensi pterygium pada nelayan di Tuminting dengan petani di Rurukan

e-CliniC ◽  
2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Yusuf S. Tangdilintin ◽  
Laya M. Rares ◽  
Yamin Tongku
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Sun Exposure ◽  
Cross Sectional ◽  
North Sulawesi ◽  
High Prevalence ◽  
High Altitude Area ◽  
Eye Examination ◽  
Low Altitude ◽  
The Difference

Abstract: Based on Riset Kesehatan Dasar 2013, North Sulawesi is one of 10 provinces in Indonesia that have the highest pterygium prevalence. Previous findings at different areas showed that pterygium is more common at areas with high altitude than at areas with low altitude. Topography of North Sulawesi with mountains and hills might be related to the high prevalence of pterygium at this province. This study was aimed to obtain the difference in pterygium prevalence at area with high altitude compared to area with low altitude at North Sulawesi. This study used a cross sectional quantitative design and was conducted at Tuminting (mean altitude about 0 km above sea level) and at Rurukan (mean altitude about 1km above sea level). There were 51 respondents at each location. Eye examination was performed and data about sun exposure were collected among fishermen at Tuminting and farmers at Rurukan. The results showed that the pterygium prevalence at Rurukan was 56.9% and at Tuminting was 41.2%. Conclusion: There was a difference in pterygium prevalence between people at high altitude area from people at low altitude area at North Sulawesi.Keywords: pterygium, altitude Abstrak: Berdasarkan hasil Riset Kesehatan Dasar 2013 Provinsi Sulawesi Utara termasuk dalam 10 provinsi dengan prevalensi pterygium tertinggi di Indonesia. Temuan sebelumnya di daerah yang lain menemukan prevalensi pterygium lebih tinggi di daerah dengan ketinggian dari permukaan laut yang tinggi dibandingkan daerah dengan ketinggian dari permukaan laut yang rendah. Topografi provinsi Sulawesi Utara yang sebagian besar terdiri dari pegunungan dan bukit-bukit mungkin berhubungan dengan tingginya prevalensi pterygium di Sulawesi Utara. Penelitian ini bertujuan untuk mendapatkan perbedaan prevalensi pterygium pada daerah dengan ketinggian yang tinggi dengan daerah dengan ketinggian yang rendah di Sulawesi Utara. Desain penelitian ialah potong lintang kuantitatif yang dilakukan di Tuminting (ketinggian rata-rata sekitar 0 km di atas permukaan laut) dan di Rurukan (ketinggian rata-rata sekitar 1 km di atas permukaan laut). Terdapat 51 responden pada tiap-tiap lokasi penelitian dan dilakukan pemeriksaan mata serta pengumpulan data mengenai paparan terhadap matahari dari responden nelayan di Tuminting dan responden petani di Rurukan. Hasil penelitian mendapatkan prevalensi pterygium di Rurukan 56,9% dan di Tuminting 41,2%. Simpulan: Terdapat perbedaan prevalensi pterygium di daerah dengan ketinggian dari permukaan laut yang tinggi (Rurukan) dibandingkan daerah dengan ketinggian dari permukaan laut yang rendah (Tuminting) di Sulawesi Utara. Kata kunci: pterygium, ketinggian daerah

Ventilation in newborn rats after gestation at simulated high altitude

1991 ◽  
Vol 70 (3) ◽  
pp. 1146-1151 ◽  
Author(s):  
R. D. Gleed ◽  
J. P. Mortola
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
High Altitude ◽  
Sea Level ◽  
Body Weight Gain ◽  
Female Rats ◽  
Metabolic Adaptation ◽  
Newborn Rats ◽  
Pregnant Rats

Pregnant rats were kept at a simulated altitude of 4,500 m (PO2 91 Torr) for the whole of gestation and returned to sea level 1 day after giving birth. During pregnancy, body weight gain and food intake were approximately 30% less than in controls at sea level. Measurements were made on the 1-day-old (HYPO) pups after a few hours at sea level. In normoxia, ventilation (VE) measured by flow plethysmography was more (+17%) and O2 consumption (VO2) measured by a manometric method was less (-19%) than in control (CONT) pups; in HYPO pups VE/VO2 was 44% greater than in CONT pups. In acute hyperoxia, VE/VO2 of HYPO and CONT pups decreased by a similar amount (15-20%), indicating some limitation in O2 availability for both groups of pups in normoxia. However, VE/VO2 of HYPO pups, even in hyperoxia, remained above (+34%) that of CONT pups. HYPO pups weighed slightly less than CONT pups, their lungs were hypoplastic, and their hearts were a larger fraction of body weight. An additional group of female rats was acclimatized (8 days) to high altitude before insemination. During pregnancy, body weight gain and food intake of these females were similar to those of pregnant rats at sea level. Measurements on the 1-day-old pups of this group were similar to those of HYPO pups. We conclude that newborn rats born after hypoxic gestation present metabolic adaptation (low VO2) and acclimatization (high VE/VO2), possibly because of hypoxemia. Maternal acclimatization before insemination substantially alters maternal growth in hypoxia but does not affect neonatal outcome.

scholarly journals COMPARISON OF INTUBATING CONDITIONS, FOLLOWING PROPOFOL WITH MUSCLE RELAXSANT AND PROFOFOL WITHOUT MUSCLE RELAXANT

2019 ◽  
Vol 3 (10) ◽  
Author(s):  
Dr. Sanjeev Kumar Agrawal ◽  
Dr. Kaushal Kumar Sahu
Keyword(s):  
Body Weight ◽  
Tracheal Intubation ◽  
Neuromuscular Blocking ◽  
Muscle Relaxants ◽  
Induction Agent ◽  
Intubating Conditions ◽  
Group I ◽  
Baseline Values ◽  
Group Ii ◽  
The Difference

Introduction:  After induction of anaesthesia, tracheal intubation is usually facilitated by the use of muscle relaxants. Neuromuscular blocking drugs, particularly Succinylcholine, may cause serious side effects, but remain in clinical use to facilitate tracheal intubation due to a lack of suitable alternatives. Recent studies have suggested that propofol provides good intubating conditions without muscle relaxants, due to its relaxing action on upper air way. A search for better and ideal intravenous induction agent has led to propofol, a 2, 6, di-isopropyl phenol which was developed following a series of investigations. Propofol reduces hypertension and tachycardia during intubation. The changes in blood pressure observed are due to both decrease in cardiac output and decrease in systemic vascular resistance. Increasing the depth of anaesthesia by administering supplementary increments of induction agent, opioids or lignocaine may improve conditions. These techniques also protect against the potentially adverse effects of tracheal intubation namely systemic, intra-cranial and intra-ocular hypertensions and tachycardia. Material and Methods: 50 patients were randomly divided into two groups of 25 patients each. Group I: 2.5 mg/kg body weight of propofol injected slowly over 20 seconds. Group II: 2.5 mg/kg body weight of propofol injected slowly over 20 seconds. After loss of eye lash reflex, induction time was noted with stop watch and then injection succinylcholine 2mg/kg body weight was injected. Patients were monitored throughout the operation E.C.G. using cardiac monitor on lead II, PaO2 with Pulse Oxymeter. Pulse and blood pressure were recorded. Results: Youngest patient was of 20 years in group I and 22 years in group II. Eldest patient was of 56 years in group I and 60 years in group II. Maximum number of patients were in 20-30 years of age 15 (60%) in group I and 11 (44%) in group II. Excellent intubating conditions were seen in 15 (60%) patients of group I and 25 (100%) patients of group II. The pre induction mean pulse rate (base line) was 103.04±13.08 and 104.56±17.14 in group I and group II respectively. There was slight decrease in pulse rate initially after induction with mean 99.92±13.87 and 98.32±14.60 in group I and group II respectively, but the difference was not statistically significant from the baseline values. (p>0.05). There was slight decrease in arterial pressure initially after induction with mean 80.88 ±6.59 and 85.31±8.71 in group I and group II respectively, but the difference was not statistically significant (P>0.05) from the baseline values. There was slight increase in mean arterial pressure just after intubation with mean 94.10 ±8.07 and 95.58±9.46 in group I and group II respectively, which was not statistically significant (p>0.05). These changes in M.A.P. values return to baseline values 5 minutes after intubation. Conclusion: Propofol 2.5mg/kg when used alone as inducing agent without the aid of any neuromuscular blocking agents produced acceptable intubating conditions, when compared to propofol, 2.5mg/kg along with succinylcholine. It was shown that there were no significant cardiovascular changes when intubation was done without relaxant after induction with propofol.

Body composition at sea level and high altitudes

1961 ◽  
Vol 16 (4) ◽  
pp. 589-592 ◽  
Author(s):  
E. PicÓn-Reátegui ◽  
Rodolfo Lozano ◽  
José Valdivieso
Keyword(s):  
Physical Activity ◽  
Body Composition ◽  
Body Weight ◽  
High Altitude ◽  
Sea Level ◽  
Total Body Water ◽  
Physical Inactivity ◽  
Caloric Intake ◽  
Extracellular Fluid ◽  
Total Body

Simultaneous determinations of total body water and extracellular fluid, using the antipyrine and sucrose infusion methods, have been carried out in 28 adult male residents at sea level and in 28 residents at an altitude of 14,900 ft. Body composition was calculated from these data. The various body spaces, expressed in percentage of body weight, were similar in the two groups, with the exception of the extracellular fluid which was greater in those in the high altitude group ( P < 0.01). Neither racial characteristics nor altitude appear to be factors generally affecting body composition. In individuals having adequate caloric intake body composition seems to be influenced principally by physical activity. In fact, physical inactivity appeared to produce a loss of active tissue and its replacement by fat. Submitted on November 2, 1960

Body and Organ Weights of Rats During Acclimatization to an Altitude of 12,470 Feet

1957 ◽  
Vol 191 (3) ◽  
pp. 598-604 ◽  
Author(s):  
Paola S. Timiras ◽  
Alvin A. Krum ◽  
Nello Pace
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Cardiac Hypertrophy ◽  
Sea Level ◽  
Normal Weight ◽  
Level Control ◽  
Organ Weights ◽  
Adrenal Enlargement ◽  
Filial Generation ◽  
Preputial Glands

Body and organ weights of sea level control rats were compared with those of rats (P) born at sea level and then exposed to 12,470 feet, and with those of rats (F2) of the second filial generation born and maintained at altitude. Body weight was significantly lower from the fifth day of age in the F2 rats than in either control or P animals. The P rats exhibited normal weight gains in the period from 1 week to 6 months at altitude; however, they showed weight loss 72 hours after reaching altitude and again after 7–10 months of exposure. Elevated hemoglobin and hematocrit values were accompanied by marked cardiac hypertrophy in all F2 rats. In the P animals hemoglobin and hematocrit values were elevated after 2 months of exposure and reached a plateau after 6 months; moderate cardiac hypertrophy was present only after 10 months at altitude. Adrenal weight was markedly increased in all P animals but not in the F2 rats. In the P rats at altitude for 24 and 72 hours adrenal enlargement was accompanied by thymic and lymphatic atrophy. Significant changes were not observed in the liver, kidneys, hypophysis, thyroid, testes and preputial glands.

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