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Biomedical subjects

E Heyder

Publications and source records attributed to E Heyder.

8 recordsLinked to original sources
PubMed1985

Carbohydrate metabolism in U.S. Navy submarine personnel.

One- and two-hour postprandial glucose and insulin values were measured in 58 submariners with 5 or more FBM patrols and in 58 non-submariners. An interrelationship between serum glucose and insulin for classifying defects in carbohydrate metabolism indicated that 55% of the submariners and 45% of the non-submariners exhibited some type of defect. Exercise appears to play an important role in the maintenance of normal carbohydrate metabolism in these subjects. Non-submariners reported engaging in significantly more exercise than did submariners. Negative correlation between exercise vs. 1 and 2-h glucose and 2-h insulin was significant for all subjects. An inverse relationship was observed between amount of exercise and the severity of carbohydrate metabolic defects in submariners and non-submariners as well as in normal weight and obese individuals. No statistical differences were found between the submariner and non-submariner groups with respect to age, % body fat, fatness (normal or obese), glycosylated hemoglobin, or family history of diabetes.

Adult↗
PubMed1979

Biochemical and hematologic profiles of 1000 submariners.

Control biochemical and hematologic data were gathered for 1017 healthy submariners who ranged in age from 19.5 to 43.5 years. Means, standard deviation, and frequency distribution are presented for 24 whole blood and serum variables and, where appropriate, for 11 urinary variables. After statistical separation of the effects of aging and length of submarine service, it has been determined that the following correlations were significant in this sample: neutrophil and leucocyte levels, serum cholesterol, and both fasting and postprandial glucose correlated positively with age; serum alkaline phosphatase levels and age correlated negatively. Age-corrected positive correlations were demonstrable between length of submarine service and both serum cholesterol content and alkaline phosphatase activity; after a loading test, glucose levels showed a negative relationship to length of submarine service. Split-sample correlation analyses verified these significant correlations, with the exception of the apparent rise in alkaline phosphatase activity with increasing length of submarine duty.

Adult↗
PubMed1979

Cardiovascular risk factors in submariners.

A sizeable group of biochemical, hematologic and physiologic variables that significantly affect the prognosis for diseases of aging, especially for coronary heart disease (CHD), were studied in 1017 submariners. Skinfold thickness in these subjects was determined to be higher than in most other groups of men of similar age; the total level of body fat was within the range of high normality. Serum cholesterol levels, cigarette smoking, relative weight, and blood pressure appeared to be the factors most directly responsible for the extent of cardiovascular risk in this group of submariners. Though submariners as a group do not apparently have appreciably higher levels of CHD risk than other American men, there was a significant tendency for total risk to increase with length of submarine service as well as with age. A similar age-independent increase in serum cholesterol correlating with length of submarine service was reported earlier. Split-sample analyses support the reliability of the age-corrected correlations of CHD risk with time of submarine service. Although no attempt was made to prove a direct relationship between alcohol consumption or coffee drinking and cardiovascular risk, there were strong correlations noted. These factors, combined with serum cholesterol levels, cigarette smoking, and relative weight, deserve consideration as potentially modifiable CHD risks.

Adipose Tissue↗
PubMed1979

Calcium, magnesium, and phosphorus metabolism, and parathyroid-calcitonin function during prolonged exposure to elevated CO2 concentrations on submarines.

Studies of calcium and phosphorus metabolism and acid-base balance were carried out on three Fleet Ballistic Missile (FBM) submarines during prolonged exposure to elevated concentrations of CO2. The average CO2 concentration in the submarine atmosphere during patrols ranged from 0.85% to 1% CO2. In the three studies, in which 9--15 subjects participated, the urinary excretion of calcium and phosphate fell during the first three weeks to a level commensurate with a decrease in plasma calcium and increase in phosphorus. In the fourth week of one patrol, a marked increase was found in urinary calcium excretion, associated with a rise in blood PCO2 and bicarbonate. Urinary calcium excretion decreased again during the 5th to 8th week, with a secondary decrease in blood pH and plasma calcium. During the third patrol, the time course of acid-base changes corresponded well with that found during the second patrol. There was a trend toward an increase in plasma calcium between the fourth and fifth week commensurate with the transient rise in pH and bicarbonate. Plasma parathyroid and calcitonin hormone activities were measured in two patrols and no significant changes were found. Hydroxyproline excretion decreased in the three-week study and remained unchanged in the second patrol, which lasted 57 days. It is suggested that during prolonged exposure to low levels of CO2 (up to 1% CO2), calcium metabolism is controlled by the uptake and release of CO2 in the bones. The resulting phases in bone buffering, rather than renal regulation, determine acid-base balance.

Acid-Base Equilibrium↗
PubMed1976

Biochemistry and hematology at decompression sickness: a case report.

A 24-year-old hospital corpsman, a volunteer in a series of dry chamber air dives to a simulated pressure equivalent to 188 FSWG (57.3 MSWG), developed left knee pain shortly after standard decompression. A tentative diagnosis of decompression sickness was made and recompression therapy was initiated with alleviation of pain occurring at 60 FSWG (18.3 MSWG). A U.S. Navy Treatment Table "5 (oxygen breathing) regimen was then selected and completed uneventfully. The subject had been undergoing biomedical evaluation for several days prior to diving; thus, a clinically diagnosed case of dysbarism with subsequent treatment was available for study. This individual was then monitored for a 10-d period. The acute phase of decompression sickness was characterized by a marked shortening of clotting time and a thrombocytopenia with accompanying increased platelet aggregates. The recovery phase was categorized by a variety of hematological and bio-chemical changes. Hemodilution, an elevated megathrombocyte index, and a tendency toward eosinopenia were evident for most of the 10-d observation period. Other persistent alterations detected during this period included a relative hyperglycemia, depressed urine Na+/K+, and increased ketosteroid excretion. These observations indicate that abatement of pain after treatment of dysbarism can be followed by the onset of a variety of biochemical and hematological changes. Moreover, complete recovery may require upwards of 10 d.

Adult↗