Hyponatremia in the general population. What does it mean?

Hyponatremia is a frequent problem in clinical practice and is known to be associated with a variety of serious adverse outcomes. Estimates from the US general population and several community-based cohorts indicate that hyponatremia is also relatively common in these settings, especially among seniors, individuals with underlying disease, and those taking a variety of prescription medications. Prevalence is greatly increased when persons with a "low normal" level of serum sodium are considered. Population-based studies have identified a U-shaped relationship between serum sodium and all-cause mortality, with the increased risk at the lower end of the distribution being seen in persons with a "low normal" level of serum sodium as well as those meeting the traditional definition of hyponatremia. The hyponatremia associated risk in epidemiologic studies is of lesser magnitude than in hospital-based studies but of great potential importance give the much larger number of persons with a low serum sodium in the general population. An important challenge for the research community is to determine whether low levels of serum sodium are a direct cause of increased risk. Population-based studies are likely to provide the best opportunity to resolve this question.

Effect of soybean protein on novel cardiovascular disease risk factors: a randomized controlled trial.

BACKGROUND/OBJECTIVES: Cardiovascular disease (CVD) is the leading cause of death in the United States and the world. Clinical trials have suggested that soybean protein lowers lipids and blood pressure. The effect of soybean protein on novel CVD risk factors has not been well studied. The objective of this study was to examine the effect of soybean protein on biomarkers of inflammation, endothelial dysfunction and adipocytokines. SUBJECTS/METHODS: The effect of 8 weeks of 40 g of soybean protein supplement (89.3 mg isoflavones), 40 g of milk protein supplement and 40 g of complex carbohydrate placebo was examined in a randomized, placebo-controlled, double-blind, three-phase crossover trial among adults in New Orleans, Louisiana and Jackson, Mississippi. Plasma levels of inflammation biomarkers (C-reactive protein, interleukin-6, tumor necrosis factor-α), endothelial dysfunction biomarkers (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, thrombomodulin) and adipocytokines (high-molecular weight adiponectin, leptin, resistin) were measured at baseline and at the end of each intervention using immunoturbidimetric and enzyme-linked immunosorbent assay techniques. RESULTS: Soy protein supplementation resulted in a significant mean net change (95% confidence interval) in plasma E-selectin of -3.93 ng/ml (-7.05 to -0.81 ng/ml; P=0.014) compared with milk protein, and in plasma leptin of -2089.8 pg/ml (-3689.3 to -490.3 pg/ml; P=0.011) compared with carbohydrate. There were no significant changes in any other risk factors. CONCLUSIONS: Soy protein supplementation may reduce levels of E-selectin and leptin. Further research is warranted to investigate the mechanisms through which protein may confer protective effects on novel CVD risk factors.

Effect of soy and milk protein supplementation on serum lipid levels: a randomized controlled trial.

BACKGROUND/OBJECTIVE: Previous clinical trials have documented that soy protein reduces low-density lipoprotein cholesterol and increases high-density lipoprotein (HDL) cholesterol compared with milk protein. However, the effect of soy protein on lipids compared with carbohydrate has not been not well studied. We examined the effect of soy and milk protein supplementation on lipids and lipoproteins compared with carbohydrate among adults without hypercholesterolemia. SUBJECTS/METHODS: We conducted a randomized, double-blind, 3-phase crossover trial among 352 US adults with serum total cholesterol level of <240 mg/dl from September 2003 to April 2008. Trial participants were assigned to 40 g/day supplementation of soy protein, milk protein or complex carbohydrate from wheat each for 8 weeks in random order with a 3-week washout period between interventions. Overnight fasting blood samples were collected at the termination of each intervention phase. RESULTS: Compared with carbohydrate, soy protein supplementation was significantly associated with a net change (95% confidence interval (CI)) in total cholesterol and total/HDL cholesterol ratio of -3.97 mg/dl (-7.63 to -0.31, P=0.03) and -0.12 (-0.23 to -0.01, P=0.03), respectively. Compared with milk protein, soy protein supplementation was significantly associated with a net change (95% CI) in HDL and total/HDL cholesterol ratio of 1.54 mg/dl (0.63 to 2.44, P=0.0009) and -0.14 (-0.22 to -0.05, P=0.001), respectively. Compared with carbohydrate, milk protein supplementation was significantly associated with a net change (95% CI) in HDL of -1.13 mg/dl (-2.05 to -0.22, P=0.02). CONCLUSIONS: This randomized controlled trial indicates that soy protein, but not milk protein, supplementation improves the lipid profile among healthy individuals.

A randomized controlled trial of dietary fiber intake on serum lipids.

OBJECTIVE: Clinical trials have indicated that water-soluble fiber from oats reduces serum cholesterol among hypercholesterolemic patients on a low-fat diet. We examined the effect of dietary fiber intake on serum lipids among persons without hypercholesterolemia. DESIGN: Randomized controlled trial. SETTING AND SUBJECTS: We recruited 110 participants who were aged 30-65 years and had a serum cholesterol level < 240 mg/dl from community. INTERVENTION: Study participants were randomly assigned to receive 8 g per day of water-soluble fiber from oat bran or a control intervention. RESULTS: At baseline, the mean levels of serum cholesterol and other measured variables were comparable between the high-fiber and control groups. Over the 3-month intervention, mean changes (95% confidence interval (CI)) in total, HDL-, and LDL-cholesterol were -2.42 mg/dl (-8.90 to 4.05 mg/dl; P = 0.46), -0.24 mg/dl (-2.19 to 1.71 mg/dl; P = 0.81), and -1.96 mg/dl (-7.32 to 3.40 mg/dl; P = 0.47) in the fiber group and -0.02 mg/dl (-5.29 to 5.26 mg/dl; P = 0.99), 1.42 mg/dl (-0.74 to 3.59 mg/dl; P = 0.19), and -0.64 mg/dl (-5.30 to 4.03 mg/dl; P = 0.79) in the control group, respectively. The net changes (95% confidence interval) in total, HDL-, and LDL-cholesterol were -2.40 mg/dl (-10.6 to 5.81 mg/dl; P = 0.56), -1.66 mg/dl (-4.55 to 1.22 mg/dl; P = 0.26) and -1.33 mg/dl (-8.33 to 5.68 mg/dl; P = 0.71), respectively. CONCLUSIONS: Our study does not support the hypothesis that water-soluble fiber intake from oat bran reduces total and LDL-cholesterol in study participants with a normal serum cholesterol level.

Sodium reduction for hypertension prevention in overweight adults: further results from the Trials of Hypertension Prevention Phase II.

Sodium reduction is efficacious for primary prevention of hypertension, but the feasibility of achieving this effect is unclear. The objective of the paper is detailed analyses of adherence to and effects of the sodium reduction intervention among overweight adults in the Trials of Hypertension Prevention, Phase II. Sodium reduction (comprehensive education and counselling about how to reduce sodium intake) was tested vs no dietary intervention (usual care) for 36-48 months. A total of 956 white and 203 black adults, ages 30-54 years, with diastolic blood pressure 83-89 mmHg, systolic blood pressure (SBP) <140 mmHg, and body weight 110-165% of gender-specific standard weight were included in the study. At 36 months, urinary sodium excretion was 40.4 mmol/24 h (24.4%) lower in sodium reduction compared to usual care participants (P<0.0001), but only 21% of sodium reduction participants achieved the targeted level of sodium excretion below 80 mmol/24 h. Adherence was positively related to attendance at face-to-face contacts. Net decreases in SBP at 6, 18, and 36 months of 2.9 (P<0.001), 2.0 (P<0.001), and 1.3 (P=0.02) mmHg in sodium reduction vs usual care were associated with an overall 18% lower incidence of hypertension (P=0.048); were relatively unchanged by adjustment for ethnicity, gender, age, and baseline blood pressure, BMI, and sodium excretion; and were observed in both black and white men and women. From these beneficial but modest results with highly motivated and extensively counselled individuals, sodium reduction sufficient to favourably influence the population blood pressure distribution will be difficult to achieve without food supply changes.

Dose-response of sodium excretion and blood pressure change among overweight, nonhypertensive adults in a 3-year dietary intervention study.

A cross-sectional dose-response relationship between sodium intake and blood pressure (BP) has been demonstrated, but evidence for a graded longitudinal effect is limited. Evaluation of BP response to sodium reduction was assessed in a 3-year lifestyle dietary intervention trial. BP changes at 18 and 36 months after enrollment were analysed according to concurrent quantitative changes in sodium excretion and by categories of success in sodium reduction among 1157 men and women, ages 30-54 years, with a diastolic BP (DBP) 83-89 mmHg, systolic BP (SBP) <140 mmHg, body weight 110-165% of sex-specific standard weight, and valid baseline urinary sodium excretion. Participants were randomized to a Sodium Reduction intervention (n=581) or Usual Care (n=576). From a 187 mmol/24 h baseline mean sodium excretion, net decreases were 44 mmol/24 h at 18 months and 38 mmol/24 h at 36 months in Sodium Reduction vs Usual Care. Corresponding net decreases in SBP/DBP were 2.0/1.4 mmHg at 18 months, and 1.7/0.9 mmHg at 36 months. Significant dose-response trends in BP change over quintiles of achieved sodium excretion were seen at both 18 (SBP and DBP) and 36 (SBP only) months; effects appeared stronger among those maintaining sodium reduction. Estimated SBP decreases per 100 mmol/24 h reduction in sodium excretion at 18 and 36 months were 2.2 and 1.3 mmHg before and 7.0 and 3.6 mmHg after correction for measurement error, respectively. DBP changes were smaller and nonsignificant at 36 months. In conclusion, incremental decreases in BP with lower sodium excretion were observed in these overweight nonhypertensive individuals.

Prevalence, awareness, treatment and control of hypertension in North America, North Africa and Asia.

Results from national surveys of prevalence, awareness, treatment and control provide the most meaningful basis for assessing the burden of hypertension in the community. National surveys conducted in a variety of countries in North America, Europe, Australia, Asia and Africa have identified a strikingly similar relationship between age and blood pressure (BP), with a progressive and steep increase in systolic BP throughout adult life and a less steep increase in diastolic BP from adolescence until the fifth or sixth decade. In most countries surveyed, there was a high prevalence of hypertension. Approximately, one quarter of all adults in the United States and Egypt had hypertension (systolic BP>/=140 mmHg or diastolic BP>/=90 mmHg or use of antihypertensive medication) in national surveys conducted in 1988-1991 and 1991-1993, respectively. The corresponding percentage was somewhat lower (14.4%) for adults surveyed in China during 1991, but temporal trends indicate that the prevalence of hypertension is increasing rapidly in that country. In the 1988-1991 national survey, more than 25% of US adults were unaware of their diagnosis, only 55% were being treated with antihypertensive medication and only 29% were on antihypertensive medication with a systolic/diastolic BP >140/90 mmHg. The situation was much worse in Egypt and China, with only 8% and <5% of adults with hypertension, respectively, being treated with antihypertensive medication and having a systolic/diastolic BP <140/90 mmHg. These survey results underscore the fact that hypertension is highly prevalent, poorly treated and controlled, and an escalating health challenge in economically developing countries.

Strategies for improvement of awareness, treatment and control of hypertension: results of a panel discussion.

High blood pressure (BP) is a major risk factor for coronary heart disease, heart failure, stroke, chronic kidney disease, end stage renal disease, and a variety of other clinically important outcomes. Results from the surveys described in this issue and elsewhere underscore a common finding that hypertension is both highly prevalent and insufficiently treated and controlled. Recognizing the differences in sampling and survey measurement techniques, the reported prevalence of hypertension (SBP/DBP >/=140/90 mmHg or treatment with antihypertensive medication) in adults exceeded 25% in all of the surveys reported in this issue. In Latvia, the prevalence of hypertension for 25-64-year-old adults in the general population was 46.1%. Control of hypertension with medication to an SBP/DBP <140/90 mmHg in the general population ranged from as low as 12% to a high of only 29%. Data from other parts of the world provide an equally distressing picture of what is (not) being accomplished in treatment and control of hypertension at the level of the general population. These data provide testimony to an urgent need for greater attention to the treatment and control of hypertension in populations around the world. This was the basis for a panel discussion at the International Society of Hypertension satellite conference The Epidemiology of Hypertension-Regional Differences in Treatment and Control. Panel participants included Drs P Whelton, S Sonkodi, DG Beevers, JG Fodor, H Elliot, R Cifkova, A Nissinen, A Javor, and there was active participation of other symposium attendees. The following summarizes key elements of the discussion and recommendations of the panel.

Prevalence of diabetes and impaired fasting glucose in the Chinese adult population: International Collaborative Study of Cardiovascular Disease in Asia (InterASIA).

AIMS/HYPOTHESIS: To estimate the prevalence of diagnosed and undiagnosed diabetes and impaired fasting glucose in the general adult population of China. METHODS: The International Collaborative Study of Cardiovascular Disease in ASIA, conducted from 2000 to 2001, included a nationally representative sample of 15 540 adults, aged 35 to 74 years. An overnight fasting blood specimen was collected to measure serum glucose and information on history of diabetes and use of hypoglycaemic medications was obtained by a standard questionnaire. Undiagnosed diabetes (fasting glucose > or =7.0 mmol/l) and impaired fasting glucose (6.1-6.9 mmol/l) were defined using the American Diabetes Association criteria. RESULTS: Prevalence of self-reported diagnosed diabetes, undiagnosed diabetes, and impaired fasting glucose in Chinese adults were 1.3%, 4.2%, and 7.3%, respectively. Overall, 5.2% or 12.7 million men and 5.8% or 13.3 million women in China aged 35 to 74 years had diabetes (self-reported diagnosis plus undiagnosed diabetes). The age-standardized prevalence of diabetes was higher in residents of northern compared to southern China (7.4% vs 5.4%, p<0.001) and in those living in urban compared to rural areas (7.8% vs 5.1%, p<0.001). CONCLUSIONS/INTERPRETATION: Our results show that the prevalence of diabetes in the adult population in China is much higher than previously reported. Three out of every four diabetes patients are undiagnosed, indicative of a lack of population-based screening programmmes and a relatively rapid and recent increase in incidence of diabetes. These results indicate that diabetes has become a major public health problem in China and underscore the need for national strategies aimed at prevention and treatment of diabetes.

Legume consumption and risk of coronary heart disease in US men and women: NHANES I Epidemiologic Follow-up Study.

BACKGROUND: Soybean protein and dietary fiber supplementation reduce serum cholesterol in randomized controlled trials. Consumption of legumes, which are high in bean protein and water-soluble fiber, may be associated with a reduced risk of coronary heart disease (CHD). METHODS: A total of 9632 men and women who participated in the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study (NHEFS) and were free of cardiovascular disease (CVD) at their baseline examination were included in this prospective cohort study. Frequency of legume intake was estimated using a 3-month food frequency questionnaire, and incidence of CHD and CVD was obtained from medical records and death certificates. RESULTS: Over an average of 19 years of follow-up, 1802 incident cases of CHD and 3680 incident cases of CVD were documented. Legume consumption was significantly and inversely associated with risk of CHD (P =.002 for trend) and CVD (P =.02 for trend) after adjustment for established CVD risk factors. Legume consumption 4 times or more per week compared with less than once a week was associated with a 22% lower risk of CHD (relative risk, 0.78; 95% confidence interval, 0.68-0.90) and an 11% lower risk of CVD (relative risk, 0.89; 95% confidence interval, 0.80-0.98). CONCLUSIONS: Our study indicates a significant inverse relationship between legume intake and risk of CHD and suggests that increasing legume intake may be an important part of a dietary approach to the primary prevention of CHD in the general population.

Effects of alcohol reduction on blood pressure: a meta-analysis of randomized controlled trials.

Alcohol drinking has been associated with increased blood pressure in epidemiological studies. We conducted a meta-analysis of randomized controlled trials to assess the effects of alcohol reduction on blood pressure. We included 15 randomized control trials (total of 2234 participants) published before June 1999 in which alcohol reduction was the only intervention difference between active and control treatment groups. Using a standard protocol, information on sample size, participant characteristics, study design, intervention methods, duration, and treatment results was abstracted independently by 3 investigators. By means of a fixed-effects model, findings from individual trials were pooled after results for each trial were weighted by the inverse of its variance. Overall, alcohol reduction was associated with a significant reduction in mean (95% confidence interval) systolic and diastolic blood pressures of -3.31 mm Hg (-2.52 to -4.10 mm Hg) and -2.04 mm Hg (-1.49 to -2.58 mm Hg), respectively. A dose-response relationship was observed between mean percentage of alcohol reduction and mean blood pressure reduction. Effects of intervention were enhanced in those with higher baseline blood pressure. Our study suggests that alcohol reduction should be recommended as an important component of lifestyle modification for the prevention and treatment of hypertension among heavy drinkers.

Dietary potassium intake and risk of stroke in US men and women: National Health and Nutrition Examination Survey I epidemiologic follow-up study.

BACKGROUND AND PURPOSE: The few prospective studies that have explored the association between dietary intake of potassium and risk of stroke have reported inconsistent findings. This study examines the relationship between dietary potassium intake and the risk of stroke in a representative sample of the US general population. METHODS: Study participants included 9805 US men and women who participated in the first National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-Up Study. Dietary potassium and total energy intake were estimated at baseline by using a 24-hour dietary recall. Incidence data for stroke and coronary heart disease were obtained from medical records and death certificates. RESULTS: Over an average of 19 years of follow up, 927 stroke events and 1847 coronary heart disease events were documented. Overall, stroke hazard was significantly different among quartiles of potassium intake (likelihood ratio P=0.03); however, a test of linear trend across quartiles did not reach a customary level of statistical significance (P=0.14). Participants consuming a low potassium diet at baseline (<34.6 mmol potassium per day) experienced a 28% higher hazard of stroke (hazard ratio 1.28, 95% CI 1.11 to 1.47; P<0.001) than other participants, after adjustment for established cardiovascular disease risk factors. CONCLUSIONS: These findings suggest that low dietary potassium intake is associated with an increased risk of stroke. However, the possibility that the association is due to residual confounding cannot be entirely ruled out in this observational study.

Effect of potassium supplementation on blood pressure in Chinese: a randomized, placebo-controlled trial.

OBJECTIVE: To examine the effect of potassium supplementation on blood pressure (BP) in a Chinese population who consume a habitual high sodium and low potassium diet. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Community sample from Beijing, China. PARTICIPANTS: A total of 150 men and women aged 35-64 years with an initial systolic BP 130-159 mmHg and/or diastolic BP 80-94 mmHg. INTERVENTIONS: Participants were randomly assigned to take 60 mmol potassium chloride supplement or placebo for 12 weeks. MAIN OUTCOME MEASURE(S): BP measurements were obtained at baseline, and at 6 weeks and 12 weeks during the trial, using random-zero sphygmomanometers. RESULTS: The average baseline urinary excretion of sodium and potassium was 182 mmol/24 h and 36 mmol/24 h. Baseline BP and other measured variables were similar between the potassium supplementation and placebo groups. In the active compared to the placebo treatment group, the urinary excretion of potassium was significantly increased by 20.6 mmol/24 h (P< 0.001) during 12 weeks of intervention. Compared to placebo, active treatment was associated with a significant reduction in systolic BP (-5.00 mmHg, 95% CI: -2.13 to -7.88 mmHg, P < 0.001) but not diastolic BP (-0.63 mmHg, 95% CI: -2.49 to1.23 mmHg, P = 0.51) during 12-week intervention. CONCLUSION: These data indicate that moderate potassium supplementation resulted in a substantial reduction in systolic BP. Our findings suggest that increased potassium intake may play an important role in the prevention and treatment of hypertension in China.

Recreational drug use: a neglected risk factor for end-stage renal disease.

Case series have suggested that heroin and cocaine users are at increased risk for renal failure, but the contribution of heroin and other addictive drugs to the incidence of end-stage renal disease (ESRD) in the general population remains unknown. To clarify this issue, we conducted a case-control study in the general population to examine associations between drug use and treated ESRD. Cases were 716 patients who started therapy for ESRD in 1991, identified through a regional registry. Controls were 361 persons of similar age (20 to 65 years) selected by random digit dialing. Main risk factors examined were the lifetime use of heroin, cocaine, and other addictive drugs, assessed by telephone interview. After adjustment for age, sex, race, socioeconomic status, and history of hypertension and diabetes, persons who had ever used heroin or other opiates (any amount) were at increased risk for ESRD (adjusted odds ratio, 19.1; 95% confidence interval, 1.7 to 208.7). After adjustment for the same sociodemographic and medical history variables, the use of cocaine or crack and psychedelic drugs was also associated with ESRD, but these associations could not be separated from the effects of heroin use.

Alcohol consumption and the incidence of hypertension: The Atherosclerosis Risk in Communities Study.

A close relationship between alcohol consumption and hypertension has been established, but it is unclear whether there is a threshold level for this association. In addition, it has infrequently been studied in longitudinal studies and in black people. In a cohort study, 8334 of the Atherosclerosis Risk in Communities (ARIC) Study participants, aged 45 to 64 years at baseline, who were free of hypertension and coronary heart disease had their blood pressures ascertained after 6 years of follow-up. Alcohol consumption was assessed by dietary interview. The type of alcoholic beverage predominantly consumed was defined by the source of the largest amount of ethanol consumed. Incident hypertension was defined as a systolic blood pressure >/=140 mm Hg or diastolic blood pressure >/=90 mm Hg or use of antihypertensive medication. There was an increased risk of hypertension in those who consumed large amounts of ethanol (>/=210 g per week) compared with those who did not consume alcohol over the 6 years of follow-up. The adjusted odds ratios (95% confidence interval) were 1.2 (0.85 to 1.67) for white men, 2.02 (1.08 to 3.79) for white women, and 2.31 (1.11 to 4.86) for black men. Only 4 black women reported drinking >210 g ethanol per week. At low to moderate levels of alcohol consumption (1 to 209 g per week), the adjusted odds ratios (95% confidence interval) were 0.88 (0.71 to 1.08) in white men, 0.89 (0.73 to 1.09) in white women, 1.71 (1.11 to 2.64) in black men, and 0.88 (0.59 to 1.33) in black women. Systolic and diastolic blood pressures were higher in black men who consumed low to moderate amounts of alcohol compared with the nonconsumers but not in the 3 other race-gender strata. Models with polynomial terms of alcohol exposure suggested a nonlinear association in white and black men. Higher levels of consumption of all types of alcoholic beverages were associated with a higher risk of hypertension for all race-gender strata. The consumption of alcohol in amounts >/=210 g per week is an independent risk factor for hypertension in free-living North American populations. The consumption of low to moderate amounts of alcohol also appears to be associated with a higher risk of hypertension in black men.

Risk factors for congestive heart failure in US men and women: NHANES I epidemiologic follow-up study.

BACKGROUND: The incidence of congestive heart failure (CHF) has been increasing steadily in the United States during the past 2 decades. We studied risk factors for CHF and their corresponding attributable risk in the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study. PARTICIPANTS AND METHODS: A total of 13 643 men and women without a history of CHF at baseline examination were included in this prospective cohort study. Risk factors were measured using standard methods between 1971 and 1975. Incidence of CHF was assessed using medical records and death certificates obtained between 1982 and 1984 and in 1986, 1987, and 1992. RESULTS: During average follow-up of 19 years, 1382 CHF cases were documented. Incidence of CHF was positively and significantly associated with male sex (relative risk [RR], 1.24; 95% confidence interval [CI], 1.10-1.39; P<.001; population attributable risk [PAR], 8.9%), less than a high school education (RR, 1.22; 95% CI, 1.04-1.42; P =.01; PAR, 8.9%), low physical activity (RR, 1.23; 95% CI, 1.09-1.38; P<.001; PAR, 9.2%), cigarette smoking (RR, 1.59; 95% CI, 1.39-1.83; P<.001; PAR, 17.1%), overweight (RR, 1.30; 95% CI, 1.12-1.52; P =.001; PAR, 8.0%), hypertension (RR, 1.40; 95% CI, 1.24-1.59; P<.001; PAR, 10.1%), diabetes (RR, 1.85; 95% CI, 1.51-2.28; P<.001; PAR, 3.1%), valvular heart disease (RR, 1.46; 95% CI, 1.17-1.82; P =.001; PAR, 2.2%), and coronary heart disease (RR, 8.11; 95% CI, 6.95-9.46; P<.001; PAR, 61.6%). CONCLUSIONS: Male sex, less education, physical inactivity, cigarette smoking, overweight, diabetes, hypertension, valvular heart disease, and coronary heart disease are all independent risk factors for CHF. More than 60% of the CHF that occurs in the US general population might be attributable to coronary heart disease.

Coffee consumption and serum lipids: a meta-analysis of randomized controlled clinical trials.

Coffee drinking has been associated with increased serum cholesterol levels in some, but not all, studies. A Medline search of the English-language literature published prior to December 1998, a bibliography review, and consultations with experts were performed to identify 14 published trials of coffee consumption. Information was abstracted independently by two reviewers using a standardized protocol. With a random-effects model, treatment effects were estimated by pooling results from individual trials after weighting the results by the inverse of total variance. A dose-response relation between coffee consumption and both total cholesterol and LDL cholesterol was identified (p < 0.01). Increases in serum lipids were greater in studies of patients with hyperlipidemia and in trials of caffeinated or boiled coffee. Trials using filtered coffee demonstrated very little increase in serum cholesterol. Consumption of unfiltered, but not filtered, coffee increases serum levels of total and LDL cholesterol.

New guidelines for potassium replacement in clinical practice: a contemporary review by the National Council on Potassium in Clinical Practice.

This article is the result of a meeting of the National Council on Potassium in Clinical Practice. The Council, a multidisciplinary group comprising specialists in cardiology, hypertension, epidemiology, pharmacy, and compliance, was formed to examine the critical role of potassium in clinical practice. The goal of the Council was to assess the role of potassium in terms of current medical practice and future clinical applications. The primary outcome of the meeting was the development of guidelines for potassium replacement therapy. These guidelines represent a consensus of the Council members and are intended to provide a general approach to the prevention and treatment of hypokalemia.

Relationship between skin color and blood pressure in egyptian adults: results from the national hypertension project.

In many, but not all societies, dark skin color is associated with high blood pressure. Whether the association between skin color and blood pressure is independent of known determinants of blood pressure remains controversial. We examined the association between skin color and blood pressure in 835 Egyptian adults (370 men and 465 women) participating in the National Hypertension Project, a national survey of hypertension prevalence and blood pressure-related complications conducted in Egypt during 1991-1993. Skin color was assessed by measuring the concentration of cutaneous melanin in an unexposed area with the use of reflectance spectrophotometry. Higher concentrations of melanin were associated with lower body mass index, less education, manual labor (among men), and a lower urinary sodium-to-potassium ratio (among women). In multivariate regression analyses adjusted for age, body mass index, and education, there was a significant nonlinear association between blood pressure and skin color among women; in the lower to intermediate range of skin pigmentation, both systolic and diastolic blood pressures were higher in women with greater concentrations of cutaneous melanin. In men, blood pressure was not associated with skin color. When we used a subjective assessment of skin color, there was no significant difference in blood pressure between black-skinned Egyptians (predominantly of Nubian descent) and fair-skinned Egyptians for either gender. While the significant relationship in women appeared to be independent of known risk factors for hypertension, residual confounding may explain the association.