Global burden of obesity in 2005 and projections to 2030

OBJECTIVES

To estimate the overall prevalence and absolute burden of overweight and obesity in the world and in various regions in 2005 and to project the global burden in 2030.

DESIGN

Pooling analysis.

DATA SOURCES

We identified sex- and age-specific prevalence of overweight and obesity in representative population samples from 106 countries, which cover approximately 88% of the world population, using MEDLINE and other computerized databases, supplemented by a manual search of references from retrieved articles.

METHODS

Sex- and age-specific prevalence of overweight and obesity were applied to the 2005 population to estimate the numbers of overweight and obese individuals in each country, each world region and the entire world. In addition, the prevalence, with and without adjusting for secular trends, were applied to the 2030 population projections to forecast the number of overweight and obese individuals in 2030.

RESULTS

Overall, 23.2% (95% confidence interval 22.8-23.5%) of the world's adult population in 2005 was overweight (24.0% in men (23.4-24.5%) and 22.4% in women (21.9-22.9%)), and 9.8% (9.6-10.0%) was obese (7.7% in men (7.4-7.9%) and 11.9% in women (11.6-12.2%)). The estimated total numbers of overweight and obese adults in 2005 were 937 million (922-951 million) and 396 million (388-405 million), respectively. By 2030, the respective number of overweight and obese adults was projected to be 1.35 billion and 573 million individuals without adjusting for secular trends. If recent secular trends continue unabated, the absolute numbers were projected to total 2.16 billion overweight and 1.12 billion obese individuals.

CONCLUSIONS

Overweight and obesity are important clinical and public health burdens worldwide. National programs for the prevention and treatment of overweight, obesity and related comorbidities and mortalities should be a public health priority.

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.

Effect of statins on risk of coronary disease: a meta-analysis of randomized controlled trials

CONTEXT

Lowering low-density lipoprotein cholesterol (LDL-C) is known to reduce risk of recurrent coronary heart disease in middle-aged men. However, this effect has been uncertain in elderly people and women.

OBJECTIVE

To estimate the risk reduction of coronary heart disease and total mortality associated with statin drug treatment, particularly in elderly individuals and women.

DATA SOURCES

Trials published in English-language journals were retrieved by searching MEDLINE (1966-December 1998), bibliographies, and authors' reference files.

STUDY SELECTION

Studies in which participants were randomized to statin or control treatment for at least 4 years and clinical disease or death was the primary outcome were included in the meta-analysis (5 of 182 initially identified).

DATA EXTRACTION

Information on sample size, study drug duration, type and dosage of statin drug, participant characteristics at baseline, reduction in lipids during intervention, and outcomes was abstracted independently by 2 authors (J.H. and S.V.) using a standardized protocol. Disagreements were resolved by consensus.

DATA SYNTHESIS

Data from the 5 trials, with 30 817 participants, were included in this meta-analysis. The mean duration of treatment was 5.4 years. Stati n drug treatment was associated with a20% reduction in total cholesterol, 28% reduction in LDL-C, 13% reduction in triglycerides, and 5% increase in high-density lipoprotein cholesterol. Overall, statin drug treatment reduced risk 31 % in major coronary events (95% confidence interval [CI], 26%-36%) and 21 % in all-cause mortality (95% CI, 14%-28%). The risk reduction in major coronary events was similar between women (29%; 95% Cl, 13 %-42 %) and men (31 %; 95% CI, 26%-35%), and between persons aged at least 65 years (32%; 95% CI, 23%-39%) and persons younger than 65 years (31 %; 95% CI, 24%-36%).

CONCLUSIONS

Our meta-analysis indicates that reduction in LDL-C associated with statin drug treatment decreases the risk of coronary heart disease and all-cause mortality. The risk reduction was similar for men and women and for elderly and middle-aged persons.

Skeletal muscle lipid content and insulin resistance: evidence for a paradox in endurance-trained athletes

We examined the hypothesis that an excess accumulation of intramuscular lipid (IMCL) is associated with insulin resistance and that this may be mediated by the oxidative capacity of muscle. Nine sedentary lean (L) and 11 obese (O) subjects, 8 obese subjects with type 2 diabetes mellitus (D), and 9 lean, exercise-trained (T) subjects volunteered for this study. Insulin sensitivity (M) determined during a hyperinsulinemic (40 mU x m(-2)min(-1)) euglycemic clamp was greater (P < 0.01) in L and T, compared with O and D (9.45 +/- 0.59 and 10.26 +/- 0.78 vs. 5.51 +/- 0.61 and 1.15 +/- 0.83 mg x min(-1)kg fat free mass(-1), respectively). IMCL in percutaneous vastus lateralis biopsy specimens by quantitative image analysis of Oil Red O staining was approximately 2-fold higher in D than in L (3.04 +/- 0.39 vs. 1.40 +/- 0.28% area as lipid; P < 0.01). IMCL was also higher in T (2.36 +/- 0.37), compared with L (P < 0.01). The oxidative capacity of muscle determined with succinate dehydrogenase staining of muscle fibers was higher in T, compared with L, O, and D (50.0 +/- 4.4, 36.1 +/- 4.4, 29.7 +/- 3.8, and 33.4 +/- 4.7 optical density units, respectively; P < 0.01). IMCL was negatively associated with M (r = -0.57, P < 0.05) when endurance-trained subjects were excluded from the analysis, and this association was independent of body mass index. However, the relationship between IMCL and M was not significant when trained individuals were included. There was a positive association between the oxidative capacity and M among nondiabetics (r = 0.37, P < 0.05). In summary, skeletal muscle of trained endurance athletes is markedly insulin sensitive and has a high oxidative capacity, despite having an elevated lipid content. In conclusion, the capacity for lipid oxidation may be an important mediator of the association between excess muscle lipid accumulation and insulin resistance.

Human immunodeficiency virus type 1 viral protein R (Vpr) arrests cells in the G2 phase of the cell cycle by inhibiting p34cdc2 activity

The Vpr accessory gene product of human immunodeficiency virus types 1 and 2 and simian immunodeficiency virus is believed to play a role in permitting entry of the viral core into the nucleus of nondividing cells. A second role for Vpr was recently suggested by Rogel et al. (M. E. Rogel, L. I. Wu, and M. Emerman, J. Virol. 69:882-888, 1995), who showed that Vpr prevents the establishment in vitro of chronically infected HIV producer cell lines, apparently by causing infected cells to arrest in the G2/M phase of the cell cycle. In cycling cells, progression from G2 to M phase is driven by activation of the p34cdc2/cyclin B complex, an event caused, in part, by dephosphorylation of two regulatory amino acids of p34cdc2 (Thr-14 and Tyr-15). We show here that Vpr arrests the cell cycle in G2 by preventing the activation of the p34cdc2/cyclin B complex. Vpr expression in cells caused p34cdc2 to remain in the phosphorylated, inactive state, p34cdc2/cyclin B complexes immunoprecipitated from cells expressing Vpr were almost completely inactive in a histone H1 kinase assay. Coexpression of a constitutively active mutant p34cdc2 molecule with Vpr relieved the G2 arrest. These findings strongly suggest that Vpr arrests cells in G2 by preventing the activation of the p34cdc2/cyclin B complex that is required for entry into M phase. In vivo, Vpr might, by preventing p34cdc2 activation, delay or prevent apoptosis of infected cells. This would increase the amount of virus each infected cell produced.

CCR3 and CCR5 are co-receptors for HIV-1 infection of microglia

Several members of the chemokine receptor family are used together with CD4 for HIV-1 entry into target cells. T cell line-tropic (T-tropic) HIV-1 viruses use the chemokine receptor CXCR4 as a co-receptor, whereas macrophage-tropic (M-tropic) primary viruses use CCR5 (refs 2-6). Individuals with defective CCR5 alleles exhibit resistance to HIV-1 infection, suggesting that CCR5 has an important role in vivo in HIV-1 replication. A subset of primary viruses can use CCR3 as well as CCR5 as a co-receptor, but the in vivo contribution of CCR3 to HIV-1 infection and pathogenesis is unknown. HIV-1 infects the central nervous system (CNS) and causes the dementia associated with AIDS. Here we report that the major target cells for HIV-1 infection in the CNS, the microglia, express both CCR3 and CCR5. The CCR3 ligand, eotaxin, and an anti-CCR3 antibody inhibited HIV-1 infection of microglia, as did MIP-1beta, which is a CCR5 ligand. Our results suggest that both CCR3 and CCR5 promote efficient infection of the CNS by HIV-1.

Skeletal muscle attenuation determined by computed tomography is associated with skeletal muscle lipid content

The purpose of this investigation was to validate that in vivo measurement of skeletal muscle attenuation (MA) with computed tomography (CT) is associated with muscle lipid content. Single-slice CT scans performed on phantoms of varying lipid concentrations revealed good concordance between attenuation and lipid concentration (r(2) = 0.995); increasing the phantom's lipid concentration by 1 g/100 ml decreased its attenuation by approximately 1 Hounsfield unit (HU). The test-retest coefficient of variation for two CT scans performed in six volunteers was 0.51% for the midthigh and 0.85% for the midcalf, indicating that the methodological variability is low. Lean subjects had significantly higher (P < 0.01) MA values (49.2 +/- 2.8 HU) than did obese nondiabetic (39.3 +/- 7.5 HU) and obese Type 2 diabetic (33.9 +/- 4. 1 HU) subjects, whereas obese Type 2 diabetic subjects had lower MA values that were not different from obese nondiabetic subjects. There was also good concordance between MA in midthigh and midcalf (r = 0.60, P < 0.01), psoas (r = 0.65, P < 0.01), and erector spinae (r = 0.77, P < 0.01) in subsets of volunteers. In 45 men and women who ranged from lean to obese (body mass index = 18.5 to 35.9 kg/m(2)), including 10 patients with Type 2 diabetes mellitus, reduced MA was associated with increased muscle fiber lipid content determined with histological oil red O staining (P = -0.43, P < 0. 01). In a subset of these volunteers (n = 19), triglyceride content in percutaneous biopsy specimens from vastus lateralis was also associated with MA (r = -0.58, P = 0.019). We conclude that the attenuation of skeletal muscle in vivo determined by CT is related to its lipid content and that this noninvasive method may provide additional information regarding the association between muscle composition and muscle function.

Effects of oral potassium on blood pressure. Meta-analysis of randomized controlled clinical trials

OBJECTIVE

To assess the effects of supplementation with oral potassium on blood pressure in humans.

DESIGN

Meta-analysis of randomized controlled trials.

DATA SOURCES

English-language articles published before July 1995.

STUDY SELECTION

Thirty-three randomized controlled trials (2609 participants) in which potassium supplementation was the only difference between the intervention and control conditions.

DATA EXTRACTION

Using a standardized protocol, 2 of us independently abstracted information on sample size, duration, study design, potassium dose, participant characteristics, and treatment results.

RESULTS

By means of a random-effects model, findings from individual trials were pooled, after results for each trial were weighted by the inverse of its variance. An extreme effect of potassium in lowering blood pressure was noted in 1 trial. After exclusion of this trial, potassium supplementation was associated with a significant reduction in mean (95% confidence interval) systolic and diastolic blood pressure of -3.11 mm Hg (-1.91 to -4.31 mm Hg) and -1.97 mm Hg (-0.52 to -3.42 mm Hg), respectively. Effects of treatment appeared to be enhanced in studies in which participants were concurrently exposed to a high intake of sodium.

CONCLUSIONS

Our results support the premise that low potassium intake may play an important role in the genesis of high blood pressure. Increased potassium intake should be considered as a recommendation for prevention and treatment of hypertension, especially in those who are unable to reduce their intake of sodium.

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.

Skeletal muscle lipid content and oxidative enzyme activity in relation to muscle fiber type in type 2 diabetes and obesity

In obesity and type 2 diabetes, skeletal muscle has been observed to have a reduced oxidative enzyme activity, increased glycolytic activity, and increased lipid content. These metabolic characteristics are related to insulin resistance of skeletal muscle and are factors potentially related to muscle fiber type. The current study was undertaken to examine the interactions of muscle fiber type in relation to oxidative enzyme activity, glycolytic enzyme activity, and muscle lipid content in obese and type 2 diabetic subjects compared with lean healthy volunteers. The method of single-fiber analysis was used on vastus lateralis muscle obtained by percutaneous biopsy from 22 lean, 20 obese, and 20 type 2 diabetic subjects (ages 35+/-1, 42+/-2, and 52+/-2 years, respectively), with values for BMI that were similar in obese and diabetic subjects (23.7+/-0.7, 33.2+/-0.8, and 31.8+/-0.8 kg/m2, respectively). Oxidative enzyme activity followed the order of type I > type IIa > type IIb, but within each fiber type, skeletal muscle from obese and type 2 diabetic subjects had lower oxidative enzyme activity than muscle from lean subjects (P < 0.01). Muscle lipid content followed a similar pattern in relation to fiber type, and within each fiber type, muscle from obese and type 2 diabetic subjects had greater lipid content (P < 0.01). In summary, based on single-fiber analysis, skeletal muscle in obese and type 2 diabetic subjects mani-fests disturbances of oxidative enzyme activity and increased lipid content that are independent of the effect of fiber type.

Passive smoking and the risk of coronary heart disease--a meta-analysis of epidemiologic studies

BACKGROUND

The effect of passive smoking on the risk of coronary heart disease is controversial. We conducted a meta-analysis of the risk of coronary heart disease associated with passive smoking among nonsmokers.

METHODS

We searched the Medline and Dissertation Abstracts Online data bases and reviewed citations in relevant articles to identify 18 epidemiologic (10 cohort and 8 case-control) studies that met prestated inclusion criteria. Information on the designs of the studies, the characteristics of the study subjects, exposure and outcome measures, control for potential confounding factors, and risk estimates was abstracted independently by three investigators using a standardized protocol.

RESULTS

Overall, nonsmokers exposed to environmental smoke had a relative risk of coronary heart disease of 1.25 (95 percent confidence interval, 1.17 to 1.32) as compared with nonsmokers not exposed to smoke. Passive smoking was consistently associated with an increased relative risk of coronary heart disease in cohort studies (relative risk, 1.21; 95 percent confidence interval, 1.14 to 1.30), in case-control studies (relative risk, 1.51; 95 percent confidence interval, 1.26 to 1.81), in men (relative risk, 1.22; 95 percent confidence interval, 1.10 to 1.35), in women (relative risk, 1.24; 95 percent confidence interval, 1.15 to 1.34), and in those exposed to smoking at home (relative risk, 1.17; 95 percent confidence interval, 1.11 to 1.24) or in the workplace (relative risk, 1.11; 95 percent confidence interval, 1.00 to 1.23). A significant dose-response relation was identified, with respective relative risks of 1.23 and 1.31 for nonsmokers who were exposed to the smoke of 1 to 19 cigarettes per day and those who were exposed to the smoke of 20 or more cigarettes per day, as compared with nonsmokers not exposed to smoke (P=0.006 for linear trend).

CONCLUSIONS

Passive smoking is associated with a small increase in the risk of coronary heart disease. Given the high prevalence of cigarette smoking, the public health consequences of passive smoking with regard to coronary heart disease may be important.

Complete genome sequence of the shrimp white spot bacilliform virus

We report the first complete genome sequence of a marine invertebrate virus. White spot bacilliform virus (WSBV; or white spot syndrome virus) is a major shrimp pathogen with a high mortality rate and a wide host range. Its double-stranded circular DNA genome of 305,107 bp contains 181 open reading frames (ORFs). Nine homologous regions containing 47 repeated minifragments that include direct repeats, atypical inverted repeat sequences, and imperfect palindromes were identified. This is the largest animal virus that has been completely sequenced. Although WSBV is morphologically similar to insect baculovirus, the two viruses are not detectably related at the amino acid level. Rather, some WSBV genes are more homologous to eukaryotic genes than viral genes. In fact, sequence analysis indicates that WSBV differs from all known viruses, although a few genes display a weak homology to herpesvirus genes. Most of the ORFs encode proteins that bear no homology to any known proteins, either suggesting that WSBV represents a novel class of viruses or perhaps implying a significant evolutionary distance between marine and terrestrial viruses. The most unique feature of WSBV is the presence of an intact collagen gene, a gene encoding an extracellular matrix protein of animal cells that has never been found in any viruses. Determination of the genome of WSBV will facilitate a better understanding of the molecular mechanism underlying the pathogenesis of the WSBV virus and will also provide useful information concerning the evolution and divergence of marine and terrestrial animal viruses at the molecular level.

Fas ligand mutation in a patient with systemic lupus erythematosus and lymphoproliferative disease

The pathogenesis of systemic lupus erythematosus (SLE) is multifactorial and multigenetic. The apoptosis genes, fas and fas ligand (fasL), are candidate contributory genes in human SLE, as mutations of these genes result in autoimmunity in several murine models of this disease. In humans, fas mutations result in a familial autoimmune lymphoproliferative syndrome, but defects in FasL have not yet been identified. In this study, DNA from 75 patients with SLE was screened by single-stranded conformational polymorphism analysis for potential mutations of the extracellular domain of FasL. A heterozygous single-stranded conformational polymorphism for FasL, was identified in one SLE patient, who exhibited lymphadenopathy. Molecular cloning and sequencing indicated that the genomic DNA of this patient contained an 84-bp deletion within exon 4 of the fasL gene, resulting in a predicted 28 amino acid in-frame deletion. Analysis of PBMC from this patient revealed decreased FasL activity, decreased activation-induced cell death, and increased T cell proliferation after activation. This is the first report of defective FasL-mediated apoptosis related to a mutation of the human Fasl, gene in a patient with SLE and suggests that fasL mutations are an uncommon cause of the disease.

Serum cholesterol in young men and subsequent cardiovascular disease

BACKGROUND

The increased risk of cardiovascular disease associated with higher serum cholesterol levels in middle-aged persons has been clearly established, but there have been few opportunities to examine a potential link between serum cholesterol levels measured in young men and clinically evident premature cardiovascular disease later in life.

METHODS

We performed a prospective study of 1017 young men (mean age, 22 years) followed for 27 to 42 years to quantify the risk of cardiovascular disease and total mortality associated with serum cholesterol levels during early adult life. The mean serum cholesterol level at entry was 192 mg per deciliter (5.0 mmol per liter).

RESULTS

During a median follow-up of 30.5 years, there were 125 cardiovascular-disease events, 97 of which were due to coronary heart disease. The serum cholesterol level at base line was strongly associated with the incidence of events related to coronary heart disease and cardiovascular disease, as well as to total mortality and mortality due to cardiovascular disease. The risks were similar whether the events occurred before or after the age of 50. In a proportional-hazards analysis adjusted for age, body-mass index (the weight in kilograms divided by the square of the height in meters), the level of physical activity, coffee intake, change in smoking status, and the incidence of diabetes and hypertension during follow-up, a difference in the serum cholesterol level at base line of 36 mg per deciliter (0.9 mmol per liter)--the difference between the 25th and 75th percentiles of cholesterol level in the study population at base line--was associated with an increased risk of cardiovascular disease (relative risk, 1.72; 95 percent confidence interval, 1.39 to 2.14), coronary heart disease (relative risk, 2.01; 95 percent confidence interval, 1.59 to 2.53), and mortality due to cardiovascular disease (relative risk, 2.02; 95 percent confidence interval, 1.23 to 3.32). A difference in the base-line serum cholesterol level of 36 mg per deciliter was significantly associated with an increased risk of death before the age of 50 (relative risk, 1.64; 95 percent confidence interval, 1.03 to 2.61), but not with the overall risk of death (relative risk, 1.21; 95 percent confidence interval, 0.93 to 1.58).

CONCLUSIONS

These findings indicate a strong association between the serum cholesterol level measured early in adult life in men and cardiovascular disease in midlife.

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.

Dietary sodium intake and subsequent risk of cardiovascular disease in overweight adults

CONTEXT

Dietary sodium is positively associated with blood pressure, and ecological and animal studies both have suggested that high dietary sodium intake increases stroke mortality.

OBJECTIVE

To examine the risk of cardiovascular disease associated with dietary sodium intake in overweight and nonoverweight persons.

DESIGN

Prospective cohort study.

SETTING

The first National Health and Nutrition Examination Survey Epidemiologic Follow-up Study, conducted in 1982-1984, 1986, 1987, and 1992.

PARTICIPANTS

Of those aged 25 to 74 years when the survey was conducted in 1971 -1975 (14407 participants), a total of 2688 overweight and 6797 nonoverweight persons were included in the analysis.

MAIN OUTCOME MEASURES

Dietary sodium and energy intake were estimated at baseline using a single 24-hour dietary recall method. Incidence and mortality data for cardiovascular disease were obtained from medical records and death certificates.

RESULTS

For overweight and nonoverweight persons, over an average of 19 years of follow-up, the total number of documented cases were as follows: 680 stroke events (210 fatal), 1727 coronary heart disease events (614 fatal), 895 cardiovascular disease deaths, and 2486 deaths from all causes. Among overweight persons with an average energy intake of 7452 kJ, a 100 mmol higher sodium intake was associated with a 32% increase (relative risk [RR], 1.32; 95% confidence interval [CI], 1.07-1.64; P = .01) in stroke incidence, 89% increase (RR, 1.89; 95% CI, 1.31-2.74; P<.001) in stroke mortality, 44% increase (RR, 1.44; 95% CI, 1.14-1.81; P = .002) in coronary heart disease mortality, 61% increase (RR, 1.61; 95% CI, 1.32-1.96; P<.001) in cardiovascular disease mortality, and 39% increase (RR, 1.39; 95% CI, 1.23-1.58; P<.001) in mortality from all causes. Dietary sodium intake was not significantly associated with cardiovascular disease risk in nonoverweight persons.

CONCLUSIONS

Our analysis indicates that high sodium intake is strongly and independently associated with an increased risk of cardiovascular disease and all-cause mortality in overweight persons.

Aspirin and risk of hemorrhagic stroke: a meta-analysis of randomized controlled trials

CONTEXT

Aspirin has been widely used to prevent myocardial infarction and ischemic stroke but some studies have suggested it increases risk of hemorrhagic stroke.

OBJECTIVE

To estimate the risk of hemorrhagic stroke associated with aspirin treatment.

DATA SOURCES

Studies were retrieved using MEDLINE (search terms, aspirin, cerebrovascular disorders, and stroke), bibliographies of the articles retrieved, and the authors' reference files.

STUDY SELECTION

All trials published in English-language journals before July 1997 in which participants were randomized to aspirin or a control treatment for at least 1 month and in which the incidence of stroke subtype was reported.

DATA EXTRACTION

Information on country of origin, sample size, duration, study design, aspirin dosage, participant characteristics, and outcomes was abstracted independently by 2 authors who used a standardized protocol.

DATA SYNTHESIS

Data from 16 trials with 55462 participants and 108 hemorrhagic stroke cases were analyzed. The mean dosage of aspirin was 273 mg/d and mean duration of treatment was 37 months. Aspirin use was associated with an absolute risk reduction in myocardial infarction of 137 events per 10000 persons (95% confidence interval [CI], 107-167; P<.001) and in ischemic stroke, a reduction of 39 events per 10000 persons (95% CI, 17-61; P<.001). However, aspirin treatment was also associated with an absolute risk increase in hemorrhagic stroke of 12 events per 10000 persons (95% CI, 5-20; P<.001). This risk did not differ by participant or study design characteristics.

CONCLUSIONS

These results indicate that aspirin therapy increases the risk of hemorrhagic stroke. However, the overall benefit of aspirin use on myocardial infarction and ischemic stroke may outweigh its adverse effects on risk of hemorrhagic stroke in most populations.

Long-term effects of weight loss and dietary sodium reduction on incidence of hypertension

To examine the long-term effects of weight loss and dietary sodium reduction on the incidence of hypertension, we studied 181 men and women who participated in the Trials of Hypertension Prevention, phase 1, in Baltimore, Md. At baseline (1987 to 1988), subjects were 30 to 54 years old and had a diastolic blood pressure (BP) of 80 to 89 mm Hg and systolic BP <160 mm Hg. They were randomly assigned to one of two 18-month lifestyle modification interventions aimed at either weight loss or dietary sodium reduction or to a usual care control group. At the posttrial follow-up (1994 to 1995), BP was measured by blinded observers who used a random-zero sphygmomanometer. Incident hypertension was defined as systolic BP > or =160 mm Hg and/or diastolic BP > or =90 mm Hg and/or treatment with antihypertensive medication during follow-up. Body weight and urinary sodium were not significantly different among the groups at the posttrial follow-up. After 7 years of follow-up, the incidence of hypertension was 18.9% in the weight loss group and 40.5% in its control group and 22.4% in the sodium reduction group and 32.9% in its control group. In logistic regression analysis adjusted for baseline age, gender, race, physical activity, alcohol consumption, education, body weight, systolic BP, and urinary sodium excretion, the odds of hypertension was reduced by 77% (odds ratio 0.23; 95% confidence interval 0.07 to 0.76; P=0.02) in the weight loss group and by 35% (odds ratio 0.65; 95% confidence interval 0.25 to 1.69; P=0.37) in the sodium reduction group compared with their control groups. These results indicate that lifestyle modification such as weight loss may be effective in long-term primary prevention of hypertension.

[Report of cancer epidemiology in China, 2015]

Objective: Data from local cancer registries were pooled to estimate cancer incidence and mortality in China, 2015. Methods: Data submitted from 501 cancer registries were checked & evaluated according to the criteria of data quality control, and 368 registries' data were qualified for the final analysis. Data were stratified by area (urban/rural), sex, age group and cancer sites, and combined with national population data to estimate cancer incidence and mortality in China, 2015. Chinese population census in 2000 and Segi's population were used for age-standardized. Results: Total population covered by 368 cancer registries were 309 553 499 (148 804 626 in urban and 160 748 873 in rural areas). The percentage of morphologically verified cases (MV) and the percentage of death certificate-only cases (DCO) accounted for 69.34% and 2.09%, respectively, and the mortality to incidence ratio was 0.61. About 3 929 000 new cancer cases were reported in 2015 and the crude incidence rate was 285.83 per 100 000 population (males and females were 305.47 and 265.21 per 100 000 population). Age-standardized incidence rates by Chinese standard population (ASIRC) and by world standard population (ASIRW) were 190.64 and 186.39 per 100 000 population, respectively, with the cumulative incidence rate (0-74 age years old) of 21.44%. The cancer incidence and ASIRC were 304.96/100 000 and 196.09/100 000 in urban areas and 261.40/100 000 and 182.70/100 000 in rural areas, respectively. About 2 338 000 cancer deaths were reported in 2015 and the cancer mortality was 170.05/100 000 (210.10/100 000 in males and 128.00/100 000 in females). Age-standardized mortality rates by Chinese standard population (ASMRC) and by world standard population (ASMRW) were 106.72/100 000 and 105.84/100 000, respectively, with the cumulative incidence rate (0-74 age years old) of 11.94%. The cancer mortality and ASMRC were 172.61/100 000 and 103.65/100 000 in urban areas and 166.79/100 000 and 110.76/100 000 in rural areas, respectively. The most common cancer cases including lung, gastric, colorectal, liver and female breast, the top 10 cancer incidence accounted for about 76.70% of all cancer new cases. The most common cancer deaths including lung, liver, gastric, esophageal and colorectal, the top 10 cancer deaths accounted for about 83.00% of all cancer deaths. Conclusions: The burden of cancer showed a continuous upward trend in China. Cancer prevention and control faces the problem of the disparity in different areas and different cancer burden between men and women. The cancer pattern in China presents the coexistence of the cancer patterns in developed and developing countries. The situation of cancer prevention and control is still serious in China.

Sequence specificity and transcriptional activation in the binding of lactoferrin to DNA

Lactoferrin, an iron-binding glycoprotein found in high concentrations in human milk and other epithelial secretions and in the secondary (specific) granules of neutrophils, is thought to be responsible for primary defence against microbial infection, mainly as a result of lactoferrin sequestration of iron required for microbial growth. Many other functions have been attributed to lactoferrin, including immunomodulation and cell growth regulation (reviewed in ref. 4). Some of these functions appear to be at least in part independent of the iron-binding activity of lactoferrin. It also has been consistently observed that lactoferrin interacts avidly with nucleic acids. Lactoferrin enhancement of the activity of natural killer and lymphokine-activated killer cells in vitro is inhibited by RNA and DNA. Lactoferrin taken up by K562 human myelogenous leukaemia cells appears in the nucleus where it is bound to DNA. We report here that binding of lactoferrin to DNA occurs under stringent conditions with distinct sequence specificity, and that interaction between lactoferrin and these sequences intracellularly leads to transcriptional activation.

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.

Autoimmune disease in mice due to integration of an endogenous retrovirus in an apoptosis gene

The MRL-lpr/lpr mouse strain is a model of systemic autoimmune disease. In this model, intrinsic defects of intrathymic T cell development include defective deletion of self-reactive T cells and expression of endogenous retroviruses. Defective deletion of self-reactive T cells in the thymus has been proposed to be due to germline mutation in the Fas apoptosis gene. Using different fragments of a Fas cDNA probe, we determined that the lpr/lpr mutation is a 5.3-kb insertion of DNA within the second intron of the Fas gene. cDNA corresponding to this region was then derived from thymic RNA from MRL-lpr/lpr and MRL- +/+ mice using the polymerase chain reaction. All thymic RNA samples from MRL-lpr/lpr mice yielded a unique product that was 168 bp larger than that of MRL- +/+ mice. Complete sequence analysis indicated that this inserted sequence had 98% homology with a sequence from the 3' long terminal repeat of the early transposon (ETn). RNA analysis indicated higher expression of ETn RNA in the thymus of MRL-lpr/lpr than MRL- +/+ mice. The interdependence of ETn expression and abnormal Fas expression was then analyzed in a CD2-Fas transgenic mouse model in which a full-length murine Fas cDNA under the regulation of the CD2 promoter and enhancer was used to correct defective Fas expression in T cells of MRL-lpr/lpr mice. In these mice, reduced thymic ETn expression was observed, confirming that high ETn expression is related to abnormal Fas expression. These results establish a link between endogenous retrovirus expression, abnormal Fas expression, and autoimmune disease.

Elevated systolic blood pressure and risk of cardiovascular and renal disease: overview of evidence from observational epidemiologic studies and randomized controlled trials

The effect of elevated blood pressure on risk of cardiovascular and renal disease has been documented in both observational epidemiologic studies and clinical trials. However, these studies have traditionally concentrated on diastolic blood pressure to characterize the risk associated with hypertension. We reviewed evidence from prospective studies and randomized controlled trials to quantify the risk associated with systolic blood pressure. Prospective studies and randomized controlled clinical trials that were published in English-language journals were retrieved using MEDLINE, bibliographies, and the authors' reference files. All retrieved publications were reviewed and information on sample size, duration, study design, antihypertensive medication, participant characteristics, and outcomes was abstracted for randomized controlled trials that reported systolic blood pressure reduction during intervention. Several prospective studies indicate that the association between systolic blood pressure and risk of coronary heart disease, stroke, and end-stage renal disease is continuous, graded, and independent. Furthermore, they suggest that the association of systolic blood pressure with these outcomes is stronger than that of diastolic blood pressure. Pooling of the data available from randomized controlled trials indicates that an average reduction of 12 to 13 mm Hg in systolic blood pressure over 4 years of follow-up is associated with a 21% reduction in coronary heart disease, 37% reduction in stroke, 25% reduction in total cardiovascular mortality, and 13% reduction in all-cause mortality rates. These data indicate that systolic blood pressure is an independent and strong predictor for risk of cardiovascular and renal disease.

Seeing the herpesvirus capsid at 8.5 A

Human herpesviruses are large and structurally complex viruses that cause a variety of diseases. The three-dimensional structure of the herpesvirus capsid has been determined at 8.5 angstrom resolution by electron cryomicroscopy. More than 30 putative alpha helices were identified in the four proteins that make up the 0.2 billion-dalton shell. Some of these helices are located at domains that undergo conformational changes during capsid assembly and DNA packaging. The unique spatial arrangement of the heterotrimer at the local threefold positions accounts for the asymmetric interactions with adjacent capsid components and the unusual co-dependent folding of its subunits.