Relationship of visceral proteins to nutritional status in chronic and acute stress.

Visceral protein levels are used as indicators of prognosis, severity of injury, and nutritional status in hospitalized patients. Clinicians often use visceral protein levels to assess efficacy of nutritional support. The purpose of this study was to test the validity of such practices. Visceral protein levels were determined in patients in a medical ICU, head injury unit, and burn unit. The serum albumin and thyroxine-binding prealbumin (TBPA) levels correlated significantly with mortality in the medical ICU patients. Burn patients had depressed albumin and TBPA concentrations over the duration of hospitalization that related to the severity of thermal injury but not to adequacy of nutritional support. Head-injured patients had depressed admission albumin and TBPA levels, with neither protein level adequately related to caloric or protein supplementation. We conclude that visceral proteins may reflect severity of injury and prognosis in critically ill hospitalized patients, but they often do not accurately reflect nutritional status or adequacy of nutritional support.

Hyperprolactinaemia in male diabetics.

We recently investigated two patients with diabetes and elevated serum prolactin levels in whom no cause of hyperprolactinaemia could be found. For this reason we measured fasting serum prolactin levels in 72 diabetic males and compared the results with those of 63 healthy males and 90 nondiabetic males attending an Impotence Clinic. The diabetic group had significantly higher serum prolactin levels (13.1 +/- 0.9 ng/ml) than the two control groups (9.9 +/- 0.6 ng/ml for normal males and 7.7 +/- 0.3 ng/ml for the non-diabetic impotent group). Eighteen percent of the diabetics studied had serum prolactin levels above the normal range for males (greater than 20 ng/ml). There was no correlation between serum prolactin levels and duration of diabetes, glycosylated haemoglobin level or presence of clinically apparent retinopathy. The correlation between serum prolactin level and fasting plasma glucose was weak though statistically significant (r = 0.26, P less than 0.05).

Impotence in medical clinic outpatients.

One thousand one hundred eighty men in a medical outpatient clinic were screened as to the presence of impotence. Four hundred one men (34%) were impotent, and of those, 188 (47%) chose to be examined for their problem. After a comprehensive evaluation the following diagnoses were obtained: medication effect, 25%; psychogenic, 14%; neurological, 7%; urologic, 6%; primary hypogonadism, 10%; secondary hypogonadism, 9%; diabetes mellitus, 9%; hypothyroidism, 5%; hyperthyroidism, 1%; hyperprolactinemia, 4%; miscellaneous, 4%; and unknown causes, 7%. The mean age of the impotent patients was 59.4 years, and the prevalence of alcoholism was 7%. Luteinizing hormone, follicle-stimulating hormone, testosterone, thyroxine, triiodothyronine (T3), T3 resin uptake, and prolactin studies were necessary to diagnose individual cases. We conclude that erectile dysfunction is a common and often overlooked problem in middle-aged men followed in a medical clinic.

Free thyroxine levels in critically ill patients. A comparison of currently available assays.

Two indices of free thyroxine (T4) and four methods of free T4 measurement were compared in 85 patients with acute illness, hospitalized in intensive care units. All of the methods of free T4 measurement in critical illness were nonspecific, and two of the methods failed to suggest hypothyroidism in two patients with primary hypothyroidism and another associated critical illness. Since the ideal screening test should be both sensitive and specific, all tests for free T4 used in this study should be interpreted with caution in severely ill patients.

Hepatic bioavailability of serum thyroid hormones in nonthyroidal illness.

Serum was obtained from 11 patients with nonthyroidal illness (NTI) and from 9 control subjects. Patients with NTI demonstrated decreased total T4 and T3 levels; increased rT3, T3 resin uptake, and percent free (dialyzable) T4 levels; and normal TSH and free T4 concentrations in vitro. In addition, the effects of control and patient sera on the first pass extraction of labeled T4 and T3 by rat liver was measured with a tissue sampling-single injection technique. The percent of total serum T4 and T3 that was transported into liver on one pass was 17 +/- 2% and 77 +/- 5%, respectively, in the case of NTI, and these values were no different from control estimates. The concentrations of total serum T4 and T3 available for transport into liver in vivo were 0.69 +/- 0.13 micrograms/100 ml and 21 +/- 2 ng/100 ml, respectively, in NTI, and these values were 46% and 18% of control values, respectively. Therefore, in contrast to in vitro estimates of free T4, in vivo measurements indicate the amount of circulating T4 or T3 that is available for transport into liver cells in NTI is reduced in proportion to the decrease in total plasma hormone.

Meal stimulation of cortisol secretion: a protein induced effect.

Cortisol and ACTH secretion was studied in 52 healthy subjects who were fasted of fed various diets: standard, high fat, high carbohydrate, high protein. Subjects fed high protein diet (4 gm/kg body weight) showed significant increases in cortisol both at 30 and 60 min after the 1200 hr meal and 30 min after the 1600 hr meal. Increases in cortisol, of a smaller magnitude, were also seen after both the 1200 and 1600 hr meals in each of the diets with 1 gm protein/kg body weight (standard, high fat, high carbohydrate). ACTH was significantly increased following the 1200 hr and 1600 hr meals with the high protein diet. We conclude that dietary protein plays an important role in meal stimulated cortisol release.

Hypothyroxinemia in critically ill patients as a predictor of high mortality.

Thyroid function was measured in 86 patients hospitalized in an intensive care unit. Two patients were found to have primary hypothyroidism and were excluded from the study. Hypothyroxinemia with normal thyroid-stimulating hormone (TSH) levels was found in 22% of the patients and was associated with a high mortality (thyroxine [T4] levels less than 3.0 micrograms/dL, 84% mortality; T4 levels of 30 to 5.0 micrograms/dL, 50% mortality; and T4 levels greater than 5.0 micrograms/dL, 15% mortality). There was a high correlation between low T4 levels and mortality.

Amphetamine-induced hyperthyroxinemia.

Four patients had high serum thyroxine (T4) concentrations during periods of heavy amphetamine abuse. After amphetamine was withdrawn, serum T4 returned to normal. Administration of amphetamine to monkeys induced a rise in serum T4; in this model the high T4 level appeared to be caused by increased serum thyrotropin. The mechanism of this effect is unclear but is presumably mediated via the hypothalamus. Awareness of transient hyperthyroxinemia due to amphetamine may allow the physician to avoid confusion with true thyrotoxicosis.