Relationship between hyperinsulinemia and angiographically defined coronary atherosclerosis in non-diabetic men.

BACKGROUND: Our aim was to estimate the relationship between hyperinsulinemia and angiographically validated coronary atherosclerosis. METHODS: 102 consecutive non-diabetic male subjects (age 48.9 +/- 9.6 years) with a body mass index 25.9 +/- 2.8 kg/m(2) referred to coronary angiography in our centre were studied. A 75-g oral glucose tolerance test (OGTT) was performed and the areas under the curve (AUC) of serum insulin and glucose were calculated. RESULTS: Discriminant analysis with stepwise forward variable selection revealed that in younger patients (<50 years), the following parameters affected positively the number of significant coronary lumen reductions: age (F=8.5, p=0.005), lnAUCinsulin (F=5.8, p=0.02), low HDL cholesterol (F=4.4, p=0.04), the smoking habit (F=4.1, p=0.05). In those >=50 years of age, exclusively age (F=5.8, p=0.02) and hyperuricemia (F=3.8, p=0.06) entered the final model. CONCLUSION: Our results indicate that in non-diabetic male subjects the association of hyperinsulinemia with the severity of coronary atherosclerosis is only seen in younger patients.

Relation between insulinaemia and lipoprotein composition in men with primary arterial hypertension with and without hypertriglyceridaemia.

The purpose of the study was to evaluate a relationship between HDL, triglyceride levels and insulinaemia in primary arterial hypertension. The study population consisted of 60 men aged 32-68 years (mean age 50.87 years, s.d. 8.4) with hypertension duration of 11.1 years (s.d. 6.4 years) who were compared with 60 normotensives matched for sex, age and BMI. We examined blood pressure, plasma lipoprotein content, sum of glucose and sum of insulinaemia (sum ins) during OGTT (oral glucose tolerance test). OGTT revealed insulin secretion almost twice as high in hypertensives (P < 0.001 sum ins 11002 microU min/ml, s.d. 4846) than in normotensives (sum ins 6662 microU min/ml, s.d. 3099). Comparison of concentration of selected VLDL components shows that hypertensives were characterised by markedly higher concentration of triglycerides (1.46 mmol/L, s.d. 0.87 in hypertensives and 1.04 mmol/L, s.d. 0.54 in normotensives), free and esterified cholesterol and protein, including apolipoprotein B than normotensives. It was also found that hypertensives had higher levels of apo CIII0 and lower levels of CIII1 VLDL than normotensives. Hypertensive patients showed also a higher frequency of apo E2 isoforms (three-fold) and apo E4 isoforms (two-fold) than healthy subjects. No changes were detected in the composition of LDL and HDL between the groups. Analysing the discriminating ability of biochemical parameters chosen in a step-wise manner it was found that sum ins and HDL, protein and cholesterol concentrations were the factors most powerfully differentiating men with hypertension from healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of prolonged L-arginine administration on blood pressure in patients with essential hypertension (EH).

L-arginine (L-Arg) was administered intravenously through 4 consecutive days to 20 males (40-63 years old) with essential hypertension (EH). Significant decrease (p < 0.02) of systolic blood pressure (SBP) was observed only during the first day of the therapy and tachyphylaxis against L-Arg was noticed. The reduction of diastolic blood pressure (DBP) was more marked (p < 0.001). Significant changes in cGMP plasma level and the nitrite/nitrate urine concentration were not observed. L-Arg caused a significant activation of fibrinolysis (p < 0.005). The decrease of platelet activity, measured by the ADP-induced aggregation, after L-Arg administration was not statistically significant. Therefore, L-Arg may play only a secondary role in the treatment of EH.

Influence of SIN-1 and sodium nitroprusside (NANP) on ox-LDL metabolism in macrophages.

Effects of NO-donors (3-morpholinosydnonimine-SIN-1 and sodium nitroprusside NaNP) on the accumulation and degradation of oxidized LDL (ox-LDL) by macrophages were studied. Ox-LDL, but not native-LDL (n-LDL) suppressed the LPS-stimulated biosynthesis of NO by macrophages. SIN-1 at low concentrations < 100 microM was without any effect while SIN-1 at high concentration (300 microM) and NaNP (30-300 microM) stimulated the accumulation and degradation of ox-LDL by macrophages. The pretreatment of macrophages with NG-monomethyl-L-arginine (L-NMMA, 3 microM) for 24 hours had the same stimulatory effect. The inhibition of endogenous formation of NO, by L-NMMA profoundly changed the pattern of action of NO-donors on ox-LDL catabolism by macrophages; the stimulatory action of SIN-1 was transformed to the inhibitory action on the accumulation and degradation of ox-LDL whereas NaNP lost its stimulatory action entirely. Our interpretation of this unexpected interactions between SIN-1, NaNP and L-NMMA is as follows. Endogenous NO in macrophages inhibits the accumulation of ox-LDL and therefore, the stimulatory effect of L-NMMA has been overcome by exogenous NO from SIN-1. However, NO at high concentrations promotes lipid accumulation in macrophages and thereby, in the absence of L-NMMA, SIN-1 at high concentrations and NaNP produced a paradoxical stimulatory effect in macrophages. NaNP is not a proper NO-donor and its mode of action differed from that of SIN-1. In conclusion, NO at low physiological concentrations keeps scavenger receptors of macrophages downregulated and hence endogenous NO may show anti-atherogenic properties.

[Decrease in the level of free cholesterol fraction HDL as a risk factor for threatened atherosclerosis in idiopathic hyperinsulinemia]. / Zmniejszenie stezenia wolnego cholesterolu frakcji HDL czynnikiem zagrozenia miazdzyca w samoistnej hiperinsulinemii.

Inversive association between concentration of plasma high density lipoprotein (HDL) components and endogenous insulin response to oral glucose uptake was observed in 89 healthy, normolipidaemic, non obese, non diabetic male subjects. Inversive correlation between sum of insulin released during oral glucose tolerance test and HDL free and esterified cholesterol as well as apolipoprotein A1 concentration were confirmed. Coexistence of increased insulin secretion and low ratio of free cholesterol concentration to esterified cholesterol and to proteins in HDL was also observed. In separate group of subjects with normal glucose tolerance in high insulin response subgroup the cholesterol (free and esterified) and protein concentrations were lower than in subgroup with low insulin response. The free cholesterol/esterified cholesterol and free cholesterol/protein (apoA1) ratios were decreased in high insulin response subgroup. It is concluded that low concentration of free cholesterol is a most significant change of HDL composition in hyperinsulinemic, healthy men.

[Stroke incidence and mortality among urban and rural populations during the 3-year period]. / Zachorowalnosc i smiertelnosc na udar mózgu w populacji wielkomiejskiej i rolniczej w okresie trzyletniej obserwacji.

In years 1984-1986 582 men and 338 women have been registered with clinical diagnosis of cerebral stroke. The respective numbers in the Tarnobrzeg province were 340 and 263. Preliminary diagnosis of cerebral stroke was confirmed according to criteria of registration in 82% of men or women from Warsaw and in 81% of men and 84% of women in the Tarnobrzeg province . Standardized incidence due to cerebral stroke was significantly higher in every of analysed years in the Warsaw population both among men and women in compare with that in the Tarnobrzeg province . In both population studied the incidence was significantly higher among men than among women. Standardized fatality during 28 days from the start of sickness was higher in the Tarnobrzeg province population than in the Warsaw population so far as both men and women are concerned. In both populations among men and women the most frequently diagnosis was acute disease of cerebral vessels.