Ella Kostiainen

Effect of Diet on Serum Lipoproteins in a Population with a High Risk of Coronary Heart Disease

The population of North Karelia, a county in Finland, has a high rate of coronary heart disease. It also has a high prevalence of hypercholesterolemia, but whether this reflects a diet rich in animal fats or is a result of genetic factors is unclear. We studied the effect on serum lipoproteins of a low-fat diet with a high ratio of polyunsaturated to saturated fatty acids in 54 middle-aged volunteers in North Karelia. Total serum cholesterol decreased, from 263 +/- 8 mg per deciliter (mean +/- S.E.) to 201 +/- 5 mg in men (P less than 0.0001) and from 239 +/- 8 to 188 +/- 8 mg in women (P less than 0.0001), along with low-density-lipoprotein cholesterol and apoprotein B. High-density lipoprotein decreased from 54 +/- 2 mg per deciliter to 44 +/- 2 in men (P less than 0.0001) and from 56 +/- 3 to 47 +/- 2 mg in women (P less than 0.0001). A small but significant reduction occurred in serum apoprotein A-I, whereas apoprotein A-II increased slightly. The individual changes in low-density-lipoprotein cholesterol correlated with those in high-density-lipoprotein cholesterol. The changes in serum lipids and apoproteins were reversed when the participants returned to their original diets. Our results suggest that the hypercholesterolemia characteristic of this population is due at least in part to dietary factors.

Acute effects of marathon running on levels of serum lipoproteins and androgenic hormones in healthy males

The acute effects of marathon (42.2 km) running on serum lipid and lipoprotein levels, particularly high-density lipoprotein (HDL) subfractions HDL2 and HDL3, and on levels of serum androgenic hormones, luteinizing hormone (LH), and testosterone were studied in 20 healthy non- champion -class joggers participating in the First North Karelian Heart Marathon. Serum triglyceride and cholesterol levels were unchanged after the marathon, whereas the lipoprotein distribution of both lipids was significantly altered. Very-low-density lipoprotein triglyceride (VLDL-TG) and cholesterol (VLDL-C) levels decreased significantly, whereas low-density lipoprotein triglyceride (LDL-TG) but not cholesterol (LDL-C) levels were increased, suggesting an accumulation of VLDL remnants in the LDL density range. HDL cholesterol (HDL-C) level rose significantly owing to an increase in HDL2-C. HDL3-C level remained the same. Serum levels of apolipoproteins A-I and A-II, the main apolipoprotein constituents of HDL, did not change during the marathon but their distribution between the HDL subfractions differed, indicating a conversion of HDL3 to HDL2. Serum levels of LH, testosterone, and sex-hormone-binding globulin (SHBG) all decreased during the marathon. The changes in levels of serum lipoproteins and androgenic hormones were not interrelated. We concluded that the short-term regulation of HDL levels during acute exhaustive exercise is controlled not by changes in serum androgenic hormones but by enhanced degradation of triglyceride-rich lipoproteins.

Dietary fat and blood pressure: an intervention study on the effects of a low-fat diet with two levels of polyunsaturated fat.

The role of dietary fat in human blood pressure control was studied among 84 middle-aged subjects (mainly couples) in two semirural communities in North Karelia, Finland. The families were randomly allocated into two groups that, after a baseline period of 2 weeks, changed their diet for a 12-week intervention period so that the proportion of energy derived from fats was similarly reduced in both groups, from 38 to 24%, but the polyunsaturated/saturated fatty acid (P/S) ratio was increased--from 0.2 to 0.9 in group I and to 0.4 in group II. After the intervention period, both groups switched back to their usual diet for a period of 5 weeks. During the intervention period, total serum cholesterol was reduced by 16% in group I and 14% in group II. Mean body weight and urinary sodium, potassium, calcium, and magnesium excretion changes were small or nonexistent. Mean systolic blood pressure decreased 4 mm Hg in group I (P less than 0.01) and 3 mm Hg in group II (P less than 0.01), and mean diastolic blood pressure decreased 5 mm Hg (P less than 0.001) and 4 mm Hg (P less than 0.01), respectively. The reductions were reversed during the switch-back period (P less than 0.01). These results confirm previous findings of the blood-pressure-reducing effect of a low-fat/high-P/S diet. Although a number of possible confounding factors can be ruled out, the dietary constituent accounting for the blood pressure change cannot be ascertained definitely. The results showed no significant further blood pressure reduction with more than a moderately increased P/S ratio when the saturated fat intake was markedly reduced.

Lack of serum cholesterol-lowering effect of skimmed milk and butter milk under controlled conditions.

The effects of skimmed milk and butter milk on the plasma concentration of cholesterol, triglyceride and high density lipoprotein cholesterol were studied in voluntary male prisoners under carefully controlled conditions. No significant differences were observed in the serum lipid or lipoprotein levels between the groups ingesting the control diet and the diets containing 2.71 of skimmed milk or 2.01 of butter milk per day for 3 weeks.

Vitamin E does not influence plasma lipoprotein metabolism in healthy subjects with normal nutritional status

The effect of a 6-week treatment with large doses (600 IU/day) of vitamin E on plasma lipoprotein metabolism has been studied in six healthy middle-aged subjects. No consistent change was observed during the treatment in the plasma concentrations of cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol or apolipoproteins AI, AII and B or in the activity of postheparin plasma lipoprotein lipase or hepatic lipase. It is concluded that vitamin E does not influence plasma lipoprotein metabolism in healthy subjects with normal nutritional status.

STIMULATION OF LIPOPROTEIN LIPASE ACTIVITY OF RAT ADIPOSE TISSUE AND POST-HEPARIN PLASMA BY N6-(PHENYLISOPROPYL)ADENOSINE

Adenosine has profound effects on adipose tissue metabolism. It is an inhibitor of 13-adrenergic stimulation of cyclic AMP accumulation [1,2] and lipolysis [2-101 in tire isolated rat fat cell. It also opposes the effects of adrenaline on phosphate uptake [ 11 ]. In vivo, tile nucleoside has been reported to lower plasma free fatty acid and glycerol concentrations [8]. The effects of adenosine are thought to be mediated by two membrane receptors, one requiring an intact ribose (R-site) and tile other one an intact purine moiety [ 12-14] (P-site). Adenosine is rapidly metabolized but its effects on the R-site [12-14] are shared by purine-substituted analogs such as N6-(phenylisopro pyl)adenosine that are not deaminated by the enzyme adenosine deaminase (EC 3.5.4.4) [15]. Lipoprotein lipase (EC 3.1.1.3.4) is the enzyme responsible for the hydrolysis and uptake of triglycerides from circulating chylomicrons and very low density lipoproteins [16-19] . The enzyme is thought to be located on the endothelial surface of the capillary bed of extrahepatic tissues and it can be released into the circulation by intravenous injection of heparin [ 16-20] . Another heparin-releasable ectoenzyme is probably located on the outer surface of the endothelial cells of the liver and it is therefore called hepatic lipase [20]. This enzyme has been suggested to hydrolyze high density lipoprotein phospholipids and triglycerides [21 ]. This work was undertaken to find out ifN6-(phenyl isopropyl)adenosine has effects on lipoprotein lipase activity and, consequently, on the uptake of circulating triglycerides into tissues. Male Lewis albino rats ( 150 -250 g body wt) were used. They were fed ad libitum with a standard chow until injected intraperitoneally with 50-300/al isotonic NaC1 with/without N6-(phenylisopropyl)adenosine, at which time food was withheld. At the times indicated, the animals were anaesthetized with ether and blood was drawn by cardiac puncture into heparinized syringes. For post-heparin plasma lipase assays, blood was drawn 2 min after intravenous injection ofheparin (2000 units/kg body wt). The blood was centrifuged and the resulting plasma was stored at 2 0 ° C until assayed. Free glycerol was estimated enzymatically by using the commercial kit no. 125 032 of BoehringerMannheim GmbH. Tile assays for porst-heparin plasma lipases and the antibody to rat hepatic lipase have been described in [22]. The method used to measure heparin-releasable lipoprotein lipase activity of adipose tissue will be presented in detail in the text. N6-(phenylisopropyl)Adenosine was a gift from Dr Harald Stork of Boehringer-Mannheim GmbH. Glyceroltri-[14C] oleate (49 mCi/mmol) was from the Radiochemical Centre (Amersham). Heparin was from Medica (ttelsinki). All other reagents were from Sigma (St Louis MO).

Relation of alcohol, physical activity, dietary fat and smoking to serum HDL and total cholesterol in young Finnish men.

The study was based on 471 men, aged 19 to 20 years, who started their compulsory military service in three military bases in Southwest, Southeast and Northern Finland in February 1982. The data were gathered by means of self-administered questionnaires. A fasting venous blood specimen was taken to determine serum HDL and total cholesterol, gamma-glutamyltransferase and thiocyanate. In this cross-sectional study a few variables based on the self-administered questionnaire explained 8% and 7% of the variation in serum HDL and total cholesterol, respectively. Our results show that easily measurable behavioural factors do contribute to serum HDL and total cholesterol levels in young men. In our study the impact of alcohol consumption on serum HCL cholesterol was greater than in most previous studies. Our findings give additional support to the hypothesis that even a very modest amount of regular physical exercise has the effect of increasing the serum HDL cholesterol level.

Intrapartum stress Sowers the concentration of high density lipoprotein cholesterol in cord plasma

Abstract. The concentration of cord plasma triglycer‐ides, total cholesterol, high density lipoprotein (HDL) cholesterol, and apoprotein AI and All has been measured in acidotic and non‐acidotic full‐term neonates without chronic maternal‐fetal problems. The level of cord plasma triglycerides was significantly increased (P<005) and that of HDL cholesterol significantly decreased (P< 0–001) in the newborns belonging to the quintile class with the lowest blood PH (≤ No differences were present between the acidotic and non‐acidotic neonates in the plasma concentrations of total cholesterol or of apoprotein AI and All. The concentration of triglycerides was increased (<005) and that of HDL cholesterol was decreased (P<005) in the infants with the longest duration of labour. No correlation was observed between the concentrations of glycerol and lipids or lipoproproteins in cord plasma. The results suggest that intrapartum stress raises plasma triglycerides and induces qualitative and quantitative changes in the plasma high density lipoprotein fraction in the newborn.

Changes in the electrophoretic pattern of the lumbar cerebrospinal fluid during fractional gas encephalography.

The changes occurring in the electrophoretic pattern of the lumbar cerebrospinal fluid during GEG were studied in 144 mental defectives. The first sample was taken immediately after lumbar puncture prior to removal of CSF and injection of contrast gas. The last of the three samples was withdrawn approximately 25 min after the first, the patient being still seated. Altogether, 316 electrophoretic analyses were made with the cellulose acetate method. The factors possibly influencing the changes in the electrophoretic pattern were investigated statistically with the aid of a computer. The following changes in the mean proportions of the CSF protein electrophoretic fractions during GEG were found, with the χ2‐test, to be significant: decrease in albumin and increase in α2‐globulin and in β‐globulin. The grade of cortical gas filling seemed to be positively correlated with the magnitude of the electrophoretic changes. Thus, for example in cases of macroventriculy, where the cortical gas filling was generally poor, the electrophoretic changes were slight. The changes seem to be mainly attributable to changes in membrane permeability due to irritation by the GEG procedure in accordance with physico‐chemical laws. The admixture of CSF from the more cranial spaces with the lumbar samples seems to be only of secondary importance, as the primary differences are also due to permeability. It is important that the clinician should be aware of these changes in behaviour of the CSF electrophoretic pattern during GEG, so as to avoid unnecessary additional work and erroneous diagnoses and conclusions. Even statistically non‐significant changes may be of clinical importance if the only sample available for CSF electrophoresis is influenced by the irritating effect of GEG.

The Electrophoretic Pattern of Cerebrospinal Fluid Proteins in the Cutis Verticis Gyrata and Mental Retardation Syndrome

The electrophoretic evaluation of the cerebrospinal fluid (CSF) proteins was performed in the cutis verticis gyrata and mental retardation (CVG-MR) syndrome, as the assumed handicapped CSF circulation