Evelyn B. Man

Serum lipids, hypertension and coronary artery disease☆☆☆

Abstract The serum lipids were measured in 115 patients who had suffered a myocardial infarction at least ten days previously and in 397 apparently healthy men of various ages. All persons studied were in the postabsorptive state. A smaller number of normal women and women who had suffered a coronary attack was also investigated. A few persons with diabetes were considered separately. Serum triglyceride concentrations were increased above 5.4 mEq./L. in 5 per cent of seventy-three normal men twenty to twenty-nine years of age, in 36 per cent of 325 normal men aged thirty and over, and in 82 per cent of all patients with coronary artery disease. High serum cholesterol concentrations or hypertension appeared to increase the risk of coronary disease in persons with high serum triglycerides, but by themselves seemed to carry little risk. An exception was the occurrence of high serum cholesterol without high serum triglycerides in a small number of patients with coronary artery disease under age fifty. At all ages, however, the vast majority of patients exhibited an increase in serum triglyceride concentration as the most characteristic abnormality.

BUTANOL-EXTRACTABLE IODINE OF SERUM

It has been demonstrated chemically that the iodine bound to proteins of the serum is predominantly composed of thyroxine (1-4). The concentration of this protein-bound or serum precipitable iodine (SPI) appears to be closely correlated with the activity of the thyroid gland (5-7). It is probably the most precise clinical criterion of such activity that has yet been extensively employed. It is, therefore, generally conceded that SPI ordinarily represents circulating thyroid hormone. In studies of medically treated hyperthyroid patients, however, a number of values for SPI proved unexpectedly high in comparison with other measures of thyroid activity (5, 7). Danowski and associates (8-10) reported that SPI of normal individuals and pregnant women rose after the administration of potassium iodide. It had also been discovered that certain iodine-containing compounds commonly used for diagnostic and therapeutic purposes formed combinations with the proteins of the serum and therefore were measured with SPI (11). For these reasons it seemed desirable to examine more closely the nature of SPI and to find a more specific measure of circulating thyroid hormone. Taurog and Chaikoff (4) utilized N-butanol to extract thyroxine-like compounds from serum. This solvent, originally employed by Leland and Foster (12), can be freed from diiodotyrosine and inorganic iodine by means of an alkaline reagent suggested by Blau (13). Taurog and Chaikoff (4) found that 73 to 93 per cent of the iodine of normal plasma behaved like thyroxine inasmuch as it remained in butanol extracts after these had been washed with Blaus reagent. Danowski and associates (8-10) compared the iodine extracted by butanol with SPI in the sera of normal individuals, pregnant women, and persons taking potassium iodide. The mean value for iodine extraced by butanol in the sera from 23 healthy

Vascular disease and serum lipids in diabetes mellitus. Observations over thirty years (1931-1961).

Excerpt The fortieth anniversary of the discovery of insulin has occasioned a summation of progress and a re-evaluation of the present state of knowledge of diabetes (1). The virtual elimination of...

THE RELATION OF NEUTRAL FAT TO LACTESCENCE OF SERUM

It has long been recognized that the cloudy or lactescent serum occurring in certain diseases contains an abnormally large amount of neutral fat (1), though a quantitative relationship between neutral fat and lactescence has not been established. In the present investigation the ultracentrifuge has been utilized to study the suspended lipid particles which are responsible for such lactescence. By analyzing a variety of clear and lactescent sera having high concentrations of one or more lipid components the relationship of neutral fat to lactescence has been verified and quantitatively defined. METHODS Serum lipids were determined before and after the removal of the suspended lipid particles by flotation in the ultracentrifuge. The technique of Van Eck, Peters, and Man (2) was modified as described below to permit

SERUM IODINE OF EUTHYROID SUBJECTS TREATED WITH DESICCATED THYROID.

The changes in serum iodine and basal metabolic rate which occur when myxedematous patients are treated with desiccated thyroid have been reported in the preceding paper (1). Many euthyroid subjects differ from myxedematous patients in their ability to tolerate comparatively large amounts of dried thyroid without manifesting significant signs or symptoms of hypermetabolism (2). In the present paper, the influence of thyroid feeding on serum iodine as well as on basal metabolism of euthyroid subjects is described, and the mechanism of euthyroid tolerance to large doses of desiccated thyroid is discussed.

SERUM IODINE FRACTIONS IN HYPERTHYROIDISM

In untreated hyperthyroid patients, blood or serum iodine has been found to be above the normal range (1). Whether this iodine occurs in a protein-like or an inorganic form has been investigated by a number of workers, employing a variety of methods (2). Previously reported experiments from this laboratory indicated that most of the iodine was contained in the serum in the organic or protein-like form (3). It was only after iodine salts had been ingested that readily demonstrable amounts of inorganic iodine were found in the blood serum of either euthyroid or hyperthyroid people. The present investigation deals with the behavior of the serum proteinbound iodine, during iodine treatment of 15 hyperthyroid patients. In comparison with other methods, Somogyis zinc sulfate precipitation (4) has proved a simple and effective technique for the separation of the iodine fractions, in 6 cc. aliquots of serum of patients receiving inorganic iodine. A study has been made of the effect on the serum proteinbound iodine of giving Lugols solution to euthyroid subjects. The kinds of iodine containing compounds precipitated by zinc sulfate and sodium hydroxide have also been investigated.

THE RELATION OF ALBUMIN TO PRECIPITABLE IODINE OF SERUM.

By correlation with clinical manifestations of thyroid disease, by comparison with basal metabolism, and serum lipids, and by studies of the effects of removal of the thyroid and the administration of thyroid substance and thyroxine, it has been established that the precipitable iodine of the blood serum is, under usual circumstances, a most accurate measure of the activity of the thyroid gland (1 to 6). There is, indeed, reason to believe that the precipitable iodine may be largely, if not chiefly, composed of thyroid hormone. Thyroxine, added to normal serum, attaches itself so firmly to the proteins that it cannot be detached by washing (2). There is some evidence that the fraction of protein with which the iodine is combined is albumin (1). If this is established, this fraction may be regarded as the normal vehicle for the thyroid hormone. In the serum of certain patients with extreme hypoalbuminemia concentrations of precipitable iodine as low as those found in myxedema have been encountered. The present paper deals with an examination of the incidence and significance of this serum iodine deficiency.

Effect of carbohydrate ingestion on postprandial lipemia.

SummaryThe present study shows that the degree of postprandial lipemia may be decreased by all factors which increase carbohydrate metabolism, such as glucose and glucagon, and increased by factors inhibiting CHO metabolism, such as fasting and epinephrine. The intensity of the lipemia is not, therefore, necessarily an indication merely of fat absorption. Attention is called to the fact that existing knowledge of fat tolerance has usually been based on the effects of test meals containing little or no carbohydrate in relation to the amount of fat.

PERMEABILITY OF CAPILLARIES TO PLASMA LIPOIDS

While it has been assumed that the capillaries are impermeable to plasma lipoids, since normal urine is practically free from lipoids, the distribution of these substances to the tissues must nevertheless involve passage through the capillary wall. Comparison of the normal serum lipoid and protein content with the lipoid and protein content of ascitic, pleural, and pericardial fluids indicates a direct relationshijl between the lipoid and protein constituents in the transudate itself, with no evident correlation of transudate and normal serum constituents. Study of serum lipoids in normal individuals after decrease in blood volume due to transudation into the lower extremities during long periods of standing showed an increase in lipoids directly proportional to the increase in proteins. As a result of these experiments it is believed that the capillary walls are ordinarily impermeable, not only to proteins but to lipoids as well, and that the latter can cross only in combination with proteins. M. H.

Effect of glucagon on alimentary lipemia.

Summary 1. In 4 of 6 normal subjects, the intravenous injections of 0.03 mg of glucagon per kg body weight 2 1/2 hours after the ingestion of a standard fat breakfast caused a reduction of serum triglyceride concentration either toward or to the postabsorptive levels within half an hour. Of the 2 exceptions one failed to display any rise in concentration of triglycerides following the fat meal, prior to glucagon injection. The second failed to have a hyperglycemic response to glucagon. The rise in concentration of his serum triglycerides could be prevented by glucagon only when he was fed additional glucose with the fat meal. 2. Concentration of nonesterified fatty acids, measured in the sera of 2 subjects decreased following glucagon administration. 3. It was concluded that the effect of glucagon on serum lipids is secondary to its hyperglycemic effect.