First Report of Anthracnose of Sunflower Sprouts Caused by Colletotrichum acutatum in New Mexico.

In December 2011, edible sunflower sprouts (Helianthus annus) of two different commercially grown cultivars (Sungrown and Tiensvold) exhibiting stem and cotyledon lesions were submitted to the New Mexico State University Plant Clinic for disease diagnosis. The sample originated from an organic farm in Santa Fe County where the grower utilizes a small indoor growing facility. Stem lesions were elongate, reddish brown, and often constricted, resulting in stem girdling. Lesions on the cotyledons were dark brown with tan centers and round to irregular in shape. In some cases, the entire cotyledon was blighted. Fungal hyphae were observed on some lesions using a dissecting microscope. Colletotrichum acutatum was isolated from stem and cotyledon lesions when symptomatic tissue was plated on water agar. Conidia were fusiform ranging from 6.4 to 18.4 µm long and 2.1 to 5.1 µm wide and averaged 11.9 µm × 3.4 µm. Spores were measured from cream-colored colonies produced on acidified potato dextrose agar. PCR amplification and sequence analysis of 5.8S ribosomal DNA and internal transcribed spacers I and II was performed using primers ITS4 and ITS6 (2). An amplification product of approximately 600 base pairs in size was directly sequenced (GenBank Accession No. JX444690). A BLAST search of the NCBI total nucleotide collection revealed a 99% identity to multiple C. acutatum (syn: C. simmondsii) isolates. Four isolates were identified as C. acutatum based on morphological characteristics and DNA analysis. Koch's postulates were performed using four isolates of the pathogen and the two commercial sunflower cultivars (Sungrown and Tiensvold) originally submitted for disease analysis. Sunflower seeds were imbibed in distilled water for 24 h then sewn into peat plugs. Prior to seed germination, 5 ml of a C. acutatum spore solution (1 × 106/ml) from each isolate was applied to five peat plugs using an atomizer. Control plants were inoculated with distilled water and otherwise treated identically. Both sunflower cultivars were inoculated with each isolate of the pathogen and the test was replicated twice. The sewn peat plugs were incubated for 5 days at 21°C and 50% relative humidity. Symptoms similar to the original samples were present on 100% of the sprouts after 5 days. PCR and sequence analysis performed on cultures obtained from lesions showed a 100% match to the original New Mexico isolates fulfilling Koch's postulates. In an indoor organic facility, such as the one in NM, this disease has the potential to be very difficult to manage and the potential to infect a high percentage of the crop resulting in significant economic losses. To our knowledge, this is the second report of C. acutatum on sunflower sprouts in the United States (1) and the first report in New Mexico. References: (1) S. T. Koike et al. Plant Dis. 93:1351, 2009. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

First Report of Phytophthora nicotianae on Bulb Onion in the United States.

Phytophthora nicotianae (synonym P. parasitica) Breda de Haan was isolated from recently harvested onion bulbs (Allium cepa) in cold storage from a commercial field in southern New Mexico. Deteriorating, water-soaked tissue from the center of four bulbs was plated onto water agar and incubated at room temperature. After 72 h, cultures of Phytophthora (identified by the presence of coenocytic hyphae and papillate sporangia) were isolated and transferred to V8 agar amended with ampicillin (250 mg/liter), rifampicin (10 mg/liter), and pimaricin (0.2% wt/vol). Isolates were identified as P. nicotianae based on morphological characteristics and DNA analysis. Sporangia were sharply papilliate, noncaducous, and ovoid to spherical. The average sporangium size was 45.9 × 39.9 µm with a length-to-width ratio of 1.15. Clamydospores, both terminal and intercalary, were spherical to ovoid and averaged 37.2 × 35.2 µm (2). PCR from whole-cell extracts was performed on four cultured isolates from the infected onion tissue using previously described primers ITS4 and ITS6, which amplify the 5.8S rDNA and ITS1 and ITS2 internal transcribed spacers (1,4). A band of approximately 890 bp was amplified and directly sequenced (GenBank Accession No. HQ398876). A BLAST search of the NCBI total nucleotide collection revealed a 100% similarity to multiple P. nicotianae isolates previously sequenced (1). To confirm the pathogenicity of the isolates, onion seedlings were inoculated with 25 ml of P. nicotionae zoospore solution (15,000 zoospores/ml). Necrosis of leaf tissue and seedling death was observed 5 days postinoculation. P. nicotianae was reisolated from the infected onion seedlings and the ITS region was sequenced to confirm its identity. P. nicotianae was previously reported in bulb onion from Australia, Taiwan (Formosa), and Zimbabwe (Rhodesia) (2). P. nicotianae was reported on bunching onions (A. fistulosum) in Hawaii in 1989 (3). Onions are an important crop in New Mexico with a total production value of 47 million dollars in 2008 (NM Agriculture Statistics 2008). This discovery of a potentially significant postharvest disease poses a threat to the onion industry in New Mexico. To our knowledge, this is the first report of P. nicotianae in bulb onion in the United States and the first report of P. nicotianae in New Mexico on any crop. References: (1) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (2) D. C. Erwin and O. K. Ribeiro. Page 56 in: Phytophthora Diseases Worldwide. The American Phytopathological Society, St Paul, MN, 1996. (3) R. D. Raabe et al. Information Text Series No. 22. University of Hawaii. Hawaii Inst. Trop. Agric. Human Resources, 1981. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

First Report of Buckeye Rot Caused by Phytophthora nicotianae in Tomato in New Mexico.

Phytophthora nicotianae Breda de Haan was isolated from turning tomato fruit (Solanum lycopersicum L.) in August 2010 from a garden in central New Mexico. Symptoms typical of buckeye rot including brown, water-soaked, necrotic lesions with concentric rings were observed on three tomato fruit. Tissue from each fruit was surface sterilized and plated onto water agar and incubated at room temperature. After 72 h, colonies of Phytophthora (identified by the presence of coenocytic hyphae and papillate sporangia) were found and subcultured by hyphal tips to V8 agar amended with ampicillin (250 mg/liter), rifampicin (10 mg/liter), and pimaricin (0.2% wt/vol). The isolates of Phytophthora were identified as P. nicotianae based on morphological characteristics and DNA analysis. Sporangia were sharply papillate, noncaducous, and ovoid to spherical. The average sporangium size was 44.5 × 35.5 µm with a length-to-width ratio of 1.26. Chlamydospores, both terminal and intercalary, were spherical to ovoid and averaged 38.9 × 37.5 µm. PCR amplification and sequence analysis on three isolates from the infected tomato tissue was performed using primers ITS4 and ITS6 that amplify the 5.8S rDNA and ITSI and ITSII internal transcribed spacers (1,2). A band of approximately 890 bp was amplified and directly sequenced (GenBank Accession No. HQ711620). A BLAST search of the NCBI total nucleotide collection revealed a 100% similarity to multiple P. nicotianae isolates previously sequenced. Pathogenicity tests with sequenced P. nicotianae isolates were performed to confirm virulence on tomato fruit. Tomatoes were surface sterilized with 95% ethanol and 0.1 ml of a P. nicotianae zoospore suspension (10,000 zoospores/ml) or sterile water was pipetted onto the surface of the tomato fruit. After 5 days in a humidity chamber, all three inoculated tomatoes had expanding water-soaked, circular lesions and the negative control showed no disease symptoms. P. nicotianae was successfully reisolated from the inoculated tomato tissue and the ITS region was sequenced to confirm its identity. Although the disease has been reported in many other states since the early 1900s, to our knowledge, this is the first report of P. nicotianae causing disease on tomato in New Mexico. References: (1) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

Low risk-factor profile and long-term cardiovascular and noncardiovascular mortality and life expectancy: findings for 5 large cohorts of young adult and middle-aged men and women.

CONTEXT: Three major coronary risk factors-serum cholesterol level, blood pressure, and smoking-increase incidence of coronary heart disease (CHD) and related end points. In previous investigations, risks for low-risk reference groups were estimated statistically because samples contained too few such people to measure risk. OBJECTIVE: To measure long-term mortality rates for individuals with favorable levels for all 3 major risk factors, compared with others. DESIGN: Two prospective studies, involving 5 cohorts based on age and sex, that enrolled persons with a range of risk factors. Low risk was defined as serum cholesterol level less than 5.17 mmol/L (<200 mg/dL), blood pressure less than orequal to 120/80 mm Hg, and no current cigarette smoking. All persons with a history of diabetes, myocardial infarction (MI), or, in 3 of 5 cohorts, electrocardiogram (ECG) abnormalities, were excluded. SETTING AND PARTICIPANTS: In 18 US cities, a total of 72144 men aged 35 through 39 years and 270671 men aged 40 through 57 years screened (1973-1975) for the Multiple Risk Factor Intervention Trial (MRFIT); in Chicago, a total of 10025 men aged 18 through 39 years, 7490 men aged 40 through 59 years, and 6229 women aged 40 through 59 years screened (1967-1973) for the Chicago Heart Association Detection Project in Industry (CHA) (N = 366559). MAIN OUTCOME MEASURES: Cause-specific mortality during 16 (MRFIT) and 22 (CHA) years, relative risks (RRs) of death, and estimated greater life expectancy, comparing low-risk subcohorts vs others by age strata. RESULTS: Low-risk persons comprised only 4.8% to 9.9% of the cohorts. All 5 low-risk groups experienced significantly and markedly lower CHD and cardiovascular disease death rates than those who had elevated cholesterol level, or blood pressure, or smoked. For example, age-adjusted RRs of CHD mortality ranged from 0.08 for CHA men aged 18 to 39 years to 0.23 for CHA men aged 40 through 59 years. The age-adjusted relative risks (RRs) for all cardiovascular disease mortality ranged from 0.15 for MRFIT men aged 35 through 39 years to 0.28 for CHA men aged 40 through 59 years. The age-adjusted RR for all-cause mortality rate ranged from 0.42 for CHA men aged 40 through 59 years to 0.60 for CHA women aged 40 through 59 years. Estimated greater life expectancy for low-risk groups ranged from 5.8 years for CHA women aged 40 through 59 years to 9.5 years for CHA men aged 18 through 39 years. CONCLUSIONS: Based on these very large cohort studies, for individuals with favorable levels of cholesterol and blood pressure who do not smoke and do not have diabetes, MI, or ECG abnormalities, long-term mortality is much lower and longevity is much greater. A substantial increase in the proportion of the population at lifetime low risk could contribute decisively to ending the CHD epidemic.

Impact of major cardiovascular disease risk factors, particularly in combination, on 22-year mortality in women and men.

BACKGROUND: The appropriateness of current cardiovascular disease (CVD) risk factor guidelines in women continues to be debated. OBJECTIVE: To present new data on the appropriateness of current CVD risk factor guidelines, for women and men, from long-term follow-up of a large population sample. METHODS: Cardiovascular disease risk factor status according to current clinical guidelines and long-term impact on mortality were determined in 8686 women and 10503 men aged 40 to 64 years at baseline from the Chicago Heart Association Detection Project in Industry; average follow-up was 22 years. RESULTS: At baseline, only 6.6% of women and 4.8% of men had desirable levels for all 3 major risk factors (cholesterol level, <5.20 mmol/L [<200 mg/dL]; systolic and diastolic blood pressure, <120 and <80 mm Hg, respectively; and nonsmoking). With control for age, race, and other risk factors, each major risk factor considered separately was associated with increased risk of death for women and men. In analyses of combinations of major risk factors, risk increased with number of risk factors. Relative risks (RRs) associated with any 2 or all 3 risk factors were similar: for coronary heart disease mortality in women, RR= 5.72 (95% confidence interval [CI], 2.35-13.93), and in men, RR = 5.51 (95% CI, 3.10-9.77); for CVD mortality in women, RR = 4.54 (95% CI, 2.33-8.84), and in men, RR = 4.12 (95% CI, 2.56-6.37); and for all-cause mortality in women, RR = 2.34 (95% CI, 1.73-3.15), and in men, RR = 3.20 (95% CI, 2.47-4.14). Absolute excess risks were high in women and men with any 2 or all 3 major risk factors. CONCLUSIONS: Combinations of major CVD risk factors place women and men at high relative, absolute, and absolute excess risk of coronary heart disease, CVD, and all-cause mortality. These findings support the value of (1) measurement of major CVD risk factors, especially in combination, for assessing long-term mortality risk and (2) current advice to match treatment intensity to the level of CVD risk in both women and men.

Microalbuminuria in nondiabetic adults: relation of blood pressure, body mass index, plasma cholesterol levels, and smoking: The Gubbio Population Study.

BACKGROUND: Evidence exists that cardiovascular risk factors influence progression toward end-stage renal failure. We tested the hypothesis that in nondiabetic middle-aged adults without macroalbuminuria, cardiovascular risk factors are related to urinary albumin excretion and prevalence of microalbuminuria, a sign of early nephropathy. METHODS: Cross-sectional analysis of data for 1567 participants in The Gubbio Population Study (677 men and 890 women), aged 45 to 64 years, without macroalbuminuria, without diabetes mellitus, and with fasting plasma glucose levels of less than 7.8 mmol/L (140 mg/ dL). Data collection included albumin and creatinine excretion in timed overnight urine collection; levels of fasting plasma cholesterol, glucose, triglycerides, creatinine, and uric acid; creatinine clearance; red blood cell sodium-lithium countertransport; blood pressure; weight; height; medical history; smoking status; and alcohol intake. Urinary albumin excretion and prevalence of microalbuminuria were the dependent variables. RESULTS: Blood pressure, plasma cholesterol levels, smoking, and body mass index significantly related to urinary albumin excretion and prevalence of microalbuminuria. In analyses with control for multiple variables, relative risk for microalbuminuria (urinary albumin excretion, 20-199 microg/min) in men and women was 2.51 and 1.62, respectively, with 18 mm Hg higher (1 SD) systolic blood pressure; 2.25 and 2.10, respectively, with 1.0-mmol/L (40 mg/dL) higher plasma cholesterol level; 1.99 and 1.91, respectively, for smokers vs nonsmokers; and 1.83 and 1.33, respectively, with 4 kg/m2 higher body mass index. Findings were similar for microalbuminuria defined as urinary albumin excretion of at least 25 microg/dL glomerular filtration rate. CONCLUSION: Major cardiovascular risk factors are independent correlates of microalbuminuria in nondiabetic middle-aged adults.

Mortality differences between black and white men in the USA: contribution of income and other risk factors among men screened for the MRFIT. MRFIT Research Group. Multiple Risk Factor Intervention Trial.

BACKGROUND: Studies of underlying differences in adult mortality between black and white individuals in the USA have been constrained by limitations of data or small study size. We investigated the extent to which differences in socioeconomic position between black and white men contribute to differences in all-cause and cause-specific mortality. METHODS: 361,662 men were screened for the Multiple Risk Factor Intervention Trial between 1973 and 1975, in 22 sites. Median family income of households by zipcode (postal) area of residence was available for 20,224 black and 300,685 white men as well as data on age, cigarette smoking, blood pressure, serum cholesterol, previous heart attack, and treatment for diabetes. We classified deaths during 16 years of follow-up into specific causes and compared differences in death rates between black men and white men, before and after adjustment for differences in income and other risk factors. FINDINGS: Age-adjusted relative risk of death (black vs white) was 1.47 (95% CI 1.42-1.53). Adjustment for diastolic blood pressure, serum cholesterol, cigarette smoking, medication for diabetes, and previous admission to hospital for heart attack decreased the relative risk to 1.40 (1.35-1.46). Adjustment for income but not the other risk factors decreased the risk to 1.19 (1.14-1.24) and adjustment for other risk factors did not alter this estimate. For cardiovascular death, relative risk on adjustment for income was decreased from 1.36 to 1.09; for cancer from 1.47 to 1.25; and for non-cardiovascular and non-cancer deaths from 1.71 to 1.26. For some specific causes of death, including prostate cancer, myeloma, and hypertensive heart disease, the higher death rates among black men did not seem to reflect differences in income. Rates of death for suicide and melanoma were lower among black than white men, as were those for coronary heart disease after adjustment for income. INTERPRETATION: Socioeconomic position is the major contributor to differences in death rates between black and white men. Differentials in mortality from some specific causes do not simply reflect differences in income, however, and more detailed investigations are needed of how differences are influenced by environmental exposures, lifetime socioeconomic conditions, lifestyle, racism, and other sociocultural and biological factors.

Baseline sodium-lithium countertransport and 6-year incidence of hypertension. The Gubbio Population Study.

BACKGROUND: Sodium-lithium countertransport (Na-Li CT) activity is high in persons with hypertension. This study investigated whether high Na-Li CT relates to development of hypertension. METHODS AND RESULTS: At the baseline visit of the Gubbio Population Study, 4210 people of the 5376 surveyed were 18 to 74 years old; of these, 1599 were hypertensive (systolic pressure > or = 140 mm Hg, or diastolic pressure > or = 90 mm Hg, or on antihypertensive drug therapy). Of the 2611 nonhypertensives, 302 did not have Na-Li CT measured and 580 did not participate in 6-year follow-up. This analysis, therefore, deals with data collected on 1729 men 18 to 74 years old and women 18 to 74 years old who at baseline were nonhypertensive and had Na-Li CT measurement. Compared with individuals who were nonhypertensive at baseline and follow-up, individuals with incident hypertension at follow-up (systolic pressure > or = 140 mm Hg, or diastolic pressure > or = 90 mm Hg, or on antihypertensive drug therapy) had higher baseline values of Na-Li CT, blood pressure, age, body mass index, plasma cholesterol, and alcohol intake (P < .05). Baseline Na-Li CT was positively associated (P < .05) with development of hypertension in quartile analysis, with highest incidence of hypertension among men and women with Na-Li CT in the highest quartile (for men, > or = 376 and for women, > or = 311 mumol Li-L red blood cells-1.h-1). In univariate logistic regression, incidence of hypertension was related to baseline value of Na-Li CT, blood pressure, age, body mass index, plasma cholesterol, and alcohol intake (P < .05). In multiple logistic regression analysis, individuals with baseline Na-Li CT higher by 127 mumol (pooled SD for men and women) had 1.23 times greater risk of incident hypertension with control for sex and baseline age, body mass index, systolic pressure, and other confounders (P < .001). CONCLUSIONS: Na-Li CT is a predictor of hypertension risk in adults.

Inverse relation of dietary protein markers with blood pressure. Findings for 10,020 men and women in the INTERSALT Study. INTERSALT Cooperative Research Group. INTERnational study of SALT and blood pressure.

BACKGROUND: The purpose of this study was to assess relations to blood pressure (BP) in individuals of markers of dietary protein in their 24-hour urine collections. METHODS AND RESULTS: INTERSALT (INTERnational study of SALT and blood pressure) was a cross-sectional study of 10020 men and women aged 20 to 59 years in 52 population-based samples in 32 countries worldwide, with quality-controlled standardized procedures and assessment of multiple possible confounders. Three measurements of dietary protein in 24-hour urine of each individual participant were studied: total nitrogen and urea as indexes of total protein intake, and sulfate as an index of sulfur-containing dietary amino acids. Repeat examination was performed in a random 8% of participants to assess reliability and to correct for regression-dilution bias. Significant independent inverse relationships were found between BP (systolic and diastolic) and both 24-hour urinary total nitrogen and urea nitrogen, with adjustment for age, sex, alcohol intake, body mass, and 24-hour urinary sodium, potassium, calcium, and magnesium. With adjustment for regression-dilution bias, it was estimated that systolic and diastolic BP were on average 3.0 and 2.5 mm Hg lower, respectively, for persons with dietary total protein intake 30% above the overall mean than for those whose dietary protein intake was 30% below the overall mean (12.94 versus 6.96 g/d urinary total nitrogen, equivalent to 81 versus 44 g/d dietary protein, respectively). For the association of these markers with diastolic BP, results were similar for younger (20- to 39-year-old) and older (40- to 59-year-old) persons and for women and men. For their relation to systolic BP, regression coefficients were larger both for those aged 40 to 59 years than for those aged 20 to 39 years and for women than for men. Nonsignificant inverse relations were recorded for urinary sulfate and BP. CONCLUSIONS: These INTERSALT findings lend support to the hypothesis that higher dietary protein intake has favorable influences on BP.

Dietary salt, nitrate and stomach cancer mortality in 24 countries. European Cancer Prevention (ECP) and the INTERSALT Cooperative Research Group.

BACKGROUND: High salt and nitrate intake are considered as risk factors for stomach cancer, but little is known about possible interactions. This ecological study examines the respective importance of both factors for stomach cancer mortality at the population level using data obtained under standardized conditions and with biochemical analyses performed in the same laboratories. METHODS: Randomly selected 24-hour urine samples from 39 populations, sampled from 24 countries (N = 5756 people for sodium, 3303 for nitrate) were obtained from the INTERSALT study. Median sodium and nitrate levels were age- and sex-standardized between ages 20-49 years and averaged per country. Ecological correlation-regression analyses were done in relation to national stomach cancer mortality rates. RESULTS: The Pearson correlation of stomach cancer mortality with sodium for the 24 countries was: 0.70 in men and 0.74 in women (both P < 0.001) and with nitrate: 0.63 (P = 0.001) in men and (P < 0.005) in women. In multiple regression of stomach cancer mortality, using sodium and nitrate as independent variables the adjusted R2 was 0.61 in men and 0.54 in women (both P < 0.001). Addition of the interaction term (sodium x nitrate) to the previous model increased the adjusted R2 to 0.77 in men, and to 0.63 in women. The analysis of this model showed that the importance of nitrate as risk factor for stomach cancer mortality increased markedly with higher sodium levels. However, the relationship of stomach cancer mortality with sodium was always stronger than with nitrate. CONCLUSIONS: Salt intake, measured as 24-hour urine sodium excretion, is likely the rate-limiting factor of stomach cancer mortality at the population level.

Twenty-four hour urinary nitrate excretion in 48 populations from 30 countries: an ECP-INTERSALT collaborative study.

BACKGROUND: There is considerable interest in the possible role of nitrate in gastric carcinogenesis, but little information on nitrate intake around the world. This is the first study to give comprehensive standardised data on nitrate excretion as a marker of intake, using 48 worldwide population samples. METHODS: Urinary nitrate excretion has been shown to be a valid measure of nitrate intake in people under 50. This report presents data on 24-hour urinary nitrate excretion from urine collections obtained in the INTERSALT study, based on random samples of men and women aged 20-49 from each of 48 population samples in 30 countries. RESULTS: There was large variation in urinary nitrate excretion both within and between samples; within-sample (individual) distributions tended to be skewed towards higher values. Median values of the samples ranged from 0.42 mmol/day (Labrador, Canada) to 3.52 (Beijing, People's Republic of China) in men and 0.44 mmol/day (Colombia) to 3.44 (Beijing) in women. Overall, median values were higher in men than women by 11% on average (higher in men in 37 of 48 population samples). Comparison by geographical region of median values for men and women combined showed relatively low values in the samples in North America and Northern Europe (range 0.46-0.88 mmol/day), slightly higher values in Western Europe and Africa (0.68-1.11), and intermediate to high values in Southern Europe, Eastern and Central Europe and India (0.86-2.47). The highest median values were found in the Far Eastern samples (up to 3.48). Median values in the Central and South American samples ranged from 0.48 mmol/day (Colombia) to 1.37 (Xingu Indians of Brazil, and Argentina). CONCLUSIONS: For the first time, these data give standardized information on urinary nitrate excretion from different geographical regions of the world, and provide a basis for the further exploration of the role of nitrate in the aetiology of disease in human populations.

Sodium-lithium countertransport and blood pressure change over time: the Gubbio study.

Sodium-lithium countertransport activity in red blood cells relates to blood pressure (BP) and the prevalence of hypertension. This study investigated in adults the relation of sodium-lithium (Na-Li) countertransport to BP change from baseline to 6-year follow-up. In the Gubbio Population Study, 4210 men and women were 18 to 74 years old at baseline (1983-1986), and 3766 had a valid baseline Na-Li countertransport measurement; of these, 2729 were reexamined at 6 years of follow-up (1989-1992) and made up the study cohort. At baseline, data collection included age, height, weight, BP, pulse rate, drug treatment, alcohol intake, ratio of sodium to potassium in spot urine, plasma cholesterol, and Na-Li countertransport in red blood cells. At 6-year follow-up, data for age, BP, and drug treatment were collected as at baseline. From baseline, average BP declined for people on antihypertensive medication at follow-up and for those with baseline BP greater than or equal to 140/90 mm Hg (systolic/diastolic) and did not change or increased for the remaining participants. In quartile and correlation analyses controlled for sex, baseline BP, and antihypertensive treatment, BP change related significantly and directly to baseline Na-Li countertransport. In multiple linear regression analyses done for the entire cohort with control for other confounders, the regression coefficient of baseline Na-Li countertransport to BP change over time was positive and borderline significant. The Na-Li countertransport coefficient was positive and significant when analyses were done with the use of a categorical value of baseline Na-Li countertransport (quartile 4 and quartiles 1 through 3 combined). In both models, the Na-Li countertransport coefficient was the strongest for people with baseline BP greater than or equal to 120/80 mm Hg or for people with baseline age of 45 years or older. In conclusion, Na-Li countertransport significantly relates to BP change over time in adults.

Intersalt revisited: further analyses of 24 hour sodium excretion and blood pressure within and across populations. Intersalt Cooperative Research Group.

OBJECTIVES: To assess further the relation in Intersalt of 24 hour urinary sodium to blood pressure of individuals and populations, and the difference in blood pressure from young adulthood into middle age. DESIGN: Standardised cross sectional study within and across populations. SETTING: 52 population samples in 32 countries. SUBJECTS: 10,074 men and women aged 20-59. MAIN OUTCOME MEASURES: Association of sodium and blood pressure from within population and cross population multiple linear regression analyses with multivariate correction for regression dilution bias. Relation of sample median daily urinary sodium excretion to difference in blood pressure with age. RESULTS: In within population analyses (n = 10,074), individual 24 hour urinary sodium excretion higher by 100 mmol (for example, 170 v 70 mmol) was associated with systolic/diastolic blood pressure higher on average by 3/0 to 6/3 mm Hg (with and without body mass in analyses). Associations were larger at ages 40-59. In cross population analyses (n = 52), sample median 24 hour sodium excretion higher by 100 mmol was associated with median systolic/diastolic pressure higher on average by 5-7/2-4 mm Hg, and estimated mean difference in systolic/diastolic pressure at age 55 compared with age 25 greater by 10-11/6 mm Hg. CONCLUSIONS: The strong, positive association of urinary sodium with systolic pressure of individuals concurs with Intersalt cross population findings and results of other studies. Higher urinary sodium is also associated with substantially greater differences in blood pressure in middle age compared with young adulthood. These results support recommendations for reduction of high salt intake in populations for prevention and control of adverse blood pressure levels.

Socioeconomic differentials in mortality risk among men screened for the Multiple Risk Factor Intervention Trial: I. White men.

OBJECTIVES: This study examined socioeconomic differentials in risk of death from a number of specific causes in a large cohort of White men in the United States. METHODS: For 300 685 White men screened for the Multiple Risk Factor Intervention Trial between 1973 and 1975, data were collected on median income of White households in the zip code of residence, age, cigarette smoking, blood pressure, serum cholesterol, previous myocardial infarction, and drug treatment for diabetes. The 31 737 deaths that occurred over the 16-year follow-up period were grouped into specific causes and related to median White family income. RESULTS: There was an inverse association between age- adjusted all-cause mortality and median family income. There was no attenuation of this association over the follow-up period, and the association was similar for the 22 clinical centers carrying out the screening. The gradient was seen for many-but not all-of the specific causes of death. Other risk factors accounted for some of the association between income and coronary heart disease and smoking-related cancers. CONCLUSIONS: Socioeconomic position, as measured by median family income of area of residence, is an important determinant of mortality risk in White men.

Socioeconomic differentials in mortality risk among men screened for the Multiple Risk Factor Intervention Trial: II. Black men.

OBJECTIVES: This study examined socioeconomic differentials in risk of death from a number of causes in a large cohort of Black men in the United States. METHODS: For 20 224 Black men screened for the Multiple Risk Factor Intervention Trial between 1973 and 1975, data were collected on median family income of Black households in zip code of residence, age, cigarette smoking, blood pressure, serum cholesterol, previous heart attack, and drug treatment for diabetes. The 2937 deaths that occurred over the 16-year follow-up period were grouped into specific causes and related to median Black family income. RESULTS: There was an inverse association between age-adjusted all-cause mortality and median family income. There was no attenuation of this association over the follow-up period, and the association was similar for the 22 clinical centers carrying out the screening. The gradient was seen for most of the specific causes of death, although the strength of the association varied. Median income was markedly lower for the Black men screened than for the White men, but the relationship between income and all-cause mortality was similar. CONCLUSIONS: Socioeconomic position is an important determinant of mortality risk for Black men. Even though Blacks lived in areas with substantially lower median family income than Whites, the association of income with mortality was similar for Blacks and Whites.

A north-south comparison of blood pressure and factors related to blood pressure in the People's Republic of China: a report from the PRC-USA Collaborative Study of Cardiovascular Epidemiology.

OBJECTIVES: To compare blood pressures in northern (Beijing) and southern (Guangzhou) Chinese population samples aged 35-54 years, males and females, urban and rural, and to assess the role of blood pressure-related traits in explaining north-south differences. DESIGN: Cross-sectional surveys were conducted in 1983-1984 of northern and southern populations employed in industry (urban) or farming (rural). METHODS: In the north samples were selected from the Capital Iron and Steel Complex (urban) and Shijingshan district (rural); in the south samples from the Guangzhou Shipyard (urban) and Panyu County (rural) were used. RESULTS: The number of subjects surveyed in north and south were 4706 and 4179, respectively: 1500 and 1052 urban males, and 717 and 914 rural males; and 1300 and 1061 urban females, and 1189 and 1152 rural females, respectively. Average systolic (SBP) and diastolic (DBP) blood pressures, were consistently higher in the north than in the south. SBP and DBP were significantly and independently related to age, body mass index, heart rate, use of antihypertensive drugs, serum triglycerides level, alcohol use (males only) and inversely to cigarette smoking. Northerners were older, taller, heavier and had higher body mass index and triglycerides level than southerners. With adjustment of SBP and DBP for blood pressure-related traits, north-south blood pressure differences decreased, but remained significant for urban males, rural males and rural females, with sizeable differences for rural samples in particular. CONCLUSIONS: North-south differences in blood pressure in these samples are accounted for only partly by north-south differences in the cited blood pressure-related traits. The role of other traits requires assessment.