Olav Per Foss

Tea consumption. Relationship to cholesterol, blood pressure, and coronary and total mortality

BACKGROUND AND METHODS The relation of tea to cholesterol, systolic blood pressure, and mortality from coronary heart disease and all causes was studied in 9,856 men and 10,233 women without history of cardiovascular disease or diabetes. All men and women 35-49 years of age from the county of Oppland (Norway) were invited to participate; the attendance rate was 90%. RESULTS Mean serum cholesterol decreased with increasing tea consumption, the linear trend coefficient corresponded to a difference of 0.24 mmol/liter (9.3 mg/dl) in men and 0.15 mmol/liter (5.8 mg/dl) in women between drinkers of less than one cup and those of five or more cups/day, when other risk factors were taken into account. Systolic blood pressure was inversely related to tea with a difference between the same two tea groups of 2.1 mm in men and 3.5 mm in women. Altogether 396 men and 237 women died from all causes, and of these 141 and 18, respectively, died from coronary heart disease during the 12-year follow-up period. The mortality rate was higher (not statistically significant) among persons drinking no tea or less than one cup compared with persons drinking one or more cups/day. This applies to men and women and to coronary heart disease and all-cause mortality. For men, the relative risk (one or more versus less than one cup) for coronary death from Cox regression was 0.64 (95% CI:0.38, 1.07).

Coffee consumption and death from coronary heart disease in middle aged Norwegian men and women.

OBJECTIVE--To study the association between number of cups of coffee consumed per day and coronary death when taking other major coronary risk factors into account. DESIGN--Men and women attending screening and followed up for a mean of 6.4 years. SETTING--Cardiovascular survey performed by ambulatory teams from the National Health Screening Service in Norway. PARTICIPANTS--All middle aged people in three counties: 19,398 men and 19,166 women aged 35-54 years who reported neither cardiovascular disease or diabetes nor symptoms of angina pectoris or intermittent claudication. MAIN OUTCOME MEASURE--Predictive value of number of cups of coffee consumed per day. RESULTS--At initial screening total serum cholesterol concentration, high density lipoprotein cholesterol concentration, blood pressure, height, and weight were measured and self reported information about smoking history, physical activity, and coffee drinking habits was recorded. Altogether 168 men and 16 women died of coronary heart disease during follow up. Mean cholesterol concentrations for men and women were almost identical and increased from the lowest to highest coffee consumption group (13.1% and 10.9% respectively). With the proportional hazards model and adjustment for age, total serum and high density lipoprotein cholesterol concentrations, systolic blood pressure, and number of cigarettes per day the coefficient for coffee corresponded to a relative risk between nine or more cups of coffee and less than one cup of 2.2 (95% confidence interval 1.1 to 4.5) for men and 5.1 (0.4 to 60.3) for women. For men the relative risk varied among the three counties. CONCLUSIONS--Coffee may affect mortality from coronary heart disease over and above its effect in raising cholesterol concentrations.

Reliability of questionnaire information on cardiovascular disease and diabetes: cardiovascular disease study in Finnmark county

In a cardiovascular disease study in Finnmark county, Norway, which was repeated after three years (1977), 12 694 men and women twice answered a questionnaire on myocardial infarction, angina pectoris, other heart diseases, atherosclerosis obliterans, stroke, and diabetes. The reliability of these data is studied by using different indicators. These indicators suggest that questionnaire information on myocardial infarction is reliable and more reliable than such information on stroke or on diabetes. For stroke the study showed an underreporting. The information from the question on other heart diseases and atherosclerosis obliterans seems so unreliable that an interpretation of such data may be difficult.

The effect of coffee on blood lipids and blood pressure. results from a Norwegian cross-sectional study, men and women, 40–42 years

The association between boiled and filter coffee consumption and levels of cholesterol, triglycerides and blood pressure was studied, including 14168 men and 14859 women. A total of 94% drank coffee, 55% of the men and 48% of the women drank more than 4 cups per day. The type of coffee consumed varied between the counties, from 11 to 49% boiled and 49 to 87% filter coffee. Serum cholesterol increased linearly with increasing coffee consumption, and most strongly for boiled coffee. Controlling for other variables gave, for boiled coffee, an 8% increase for men and 10% for women. For filter coffee drinkers the coffee dose-cholesterol association remained significant only for women. Triglycerides showed a negative association with coffee, significant after adjustment for other variables. This effect was stronger for filter than for boiled coffee in both sexes. For men and women drinking 1 cup of coffee or more, a significant negative association between both systolic and diastolic blood pressure and number of cups of filter coffee was found. The influence of high consumption of different coffee-types on death rate from coronary heart disease is discussed.

Effects of lovastatin alone and in combination with cholestyramine on serum lipids and apolipoproteins in heterozygotes for familial hypercholesterolemia

We have studied the effect of lovastatin, an inhibitor of the rate-limiting enzyme in cholesterol biosynthesis (3-hydroxy-3-methylglutaryl coenzyme A reductase), alone and in combination with the bile acid sequestrant cholestyramine on lipid parameters in 30 heterozygous patients with familial hypercholesterolemia (FH) during a 20-week open trial. Lovastatin 40 mg bid (twice daily) decreased significantly total serum cholesterol, low density lipoprotein (LDL)-cholesterol, triglycerides and apolipoprotein B by 36%, 45%, 29% and 11%, respectively, while high density lipoprotein (HDL)-cholesterol and apolipoprotein A-I were increased significantly by 16% and 37%, respectively. These data are consistent with a reduction in both the number of LDL particles and in their cholesterol content. Addition of cholestyramine 4 g bid caused a significant further decrease in total serum cholesterol and LDL-cholesterol to a total of 43% and 61%, respectively. The addition of 4 g bid or 8 g bid of cholestyramine caused only minor changes in the other lipid parameters. No effect was found by these drugs on Lp(a) lipoprotein level. We conclude that lovastatin alone or in combination with a small dose of cholestyramine normalizes the lipid profile in most FH heterozygotes.

Serum glucose levels during long-term observation of treated and untreated men with mild hypertension: The Oslo study

Serum glucose levels, triglyceride levels, and body weight are reported from a controlled drug trial in men, aged 40 to 49, with uncomplicated mild hypertension. The drug treatment started with hydrochlorothiazide alone, and methyldopa was added when necessary. If side effects occurred, methyldopa was replaced by propranolol. No detailed advice about diet, smoking, or weight reduction was given to any group. The untreated control subjects had a small increase in serum glucose levels during five years, from 6.08 to 6.21 mmol/liter. Those treated with hydrochlorothiazide alone and those treated with hydrochlorothiazide plus methyldopa had a small increase in serum glucose levels of the same order as that in the control subjects. However, those receiving the thiazide/propranolol combination experienced a sizeable increase in glucose levels, from 5.96 to 6.53 mmol/liter (p less than 0.001). This increase was significantly greater than the increase in the other groups (p less than 0.001). The thiazide/propranolol group also showed a significant increase in serum triglyceride levels (p less than 0.05). There was no difference in serum potassium levels in the different drug groups. The results indicate that moderate thiazide doses do not have significant effects on serum glucose levels in this age group. Propranolol in combination with thiazide seems to increase the level of serum glucose.

The effect on HDL cholesterol of oxprenolol and atenolol

In 19 healthy men aged 50 with untreated mild essential hypertension (WHO group I classification) randomized into two groups, treatment (18 weeks) with oxprenolol (n = 10) lowered HDL cholesterol by 11.4% (P less than 0.02) and cholesterol ratio (HDL cholesterol X 100/LDL + VLDL cholesterol) by 13.7% (P less than 0.05) whereas atenolol (n = 9) lowered HDL cholesterol by 16.5% (P less than 0.02) and cholesterol ratio by 19.2% (P less than 0.01). In the total material (n = 19) the reduction of HDL cholesterol correlated positively with initial concentration of HDL (r = 0.48, P less than 0.05). Increments of total triglycerides by 20.0 and 17.9%, respectively, for the two drugs and small changes in total cholesterol, LDL + VLDL cholesterol and uric acid were not significant. The HDL cholesterol lowering effect of oxprenolol and atenolol observed in the present study may have clinical importance since such metabolic side effects have been postulated to counteract the beneficial effect of blood pressure reduction on development of atherosclerosis and coronary heart disease in mild essential hypertension.

Increased platelet release reaction in 50-year-old men with essential hypertension: Correlation with atherogenic cholesterol fractions

Beta-thromboglobulin (BTG) is a platelet-specific release product. Plasma BTG was significantly increased (p less than 0.01) in 50-year-old, untreated essential hypertensive men (1.22 +/- 0.13 nmol/L, n = 39, mean +/- SE) compared to 50-year-old, healthy normotensive control men (0.82 +/- 0.07 nmol/L, n = 31). Plasma BTG in the hypertensive group correlated significantly with the total serum cholesterol concentration (r = 0.47, p less than 0.01) and with the atherogenic cholesterol fractions low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) cholesterol (r = 0.50, p less than 0.01). In the normotensive group, no significant correlation was observed between plasma BTG and total serum cholesterol (r = 0.14) or between plasma BTG and LDL + VLDL cholesterol (r = 0.08). Neither was any significant correlation found between plasma BTG and serum high-density lipoprotein (HDL) cholesterol or total triglycerides in either group. Thus, middle-aged men with untreated essential hypertension have an increased blood platelet release reaction related to their concentrations of atherogenic blood lipids. This relationship may be of pathogenetic importance for atherogenesis in hypertension.

Effects of posture on serum cholesterol fractions, cholesterol ratio and triglycerides

In 41 healthy men aged 50 fasting serum HDL cholesterol, total cholesterol, LDL + VLDL cholesterol and triglycerides increased by 8.3, 9.6, 9.9 and 11.3%, respectively (all P less than 0.001), after 30 min standing compared to 30 min in the supine position. These findings can be fully explained by decrease in plasma volume on changing from lying to the erect position. However, the cholesterol ratio (HDL cholesterol X 100/LDL + VLDL cholesterol) was not influenced by posture and should be evaluated instead of cholesterol fractions if the conditions for blood sampling were not controlled.

Reliability of the Reflotron in the determination of cholesterol

Measurements of total cholesterol in the field by means of the Reflotron dry-chemistry system (capillary blood) were compared to total cholesterol obtained by a standardized conventional wet-chemistry method in a clinico-chemical laboratory (serum). A total of 1200 people participated in the study. Two identical Reflotron machines were used. In the first period of the study an excellent agreement was found between Reflotron measurements of a reference serum provided by the manufacturer (mean, 4.99 mmol/l; CV, 1.8%) and the stated value (4.97 mmol/l). In the rest of the study higher values and greater variation were found with the Reflotron (mean, 5.32 mmol/l; CV 5.2%). Clearly the Reflotron measurements in the latter period of study were not reliable. In the period with stable instruments most of the values obtained at the two Reflotron machines differed from each other by less than 10%, with a mean difference of 0.08 mmol/l. Reflotron (both machines) and wet-chemistry measurements agreed well for the first 500 participants in the study (mean difference, Reflotron-wet-chemistry, -0.008 mmol/l; 95% confidence interval, -0.035 to 0.019 mmol/l; correlation, 0.967). In this period most Reflotron values differed from wet-chemistry values by less than 9% below to 9% above. With the next 200 participants the Reflotron gave on average slightly higher values than wet-chemistry measurements. The coefficients of variation for measurement variation were higher for Reflotron that for wet-chemistry even in the period with stable instruments. In all parts of the study period a lower HDL-cholesterol level was associated with larger differences between total cholesterol determined by Reflotron and wet-chemistry.