The Influence of Sodium and Potassium Intake and Insulin Resistance on Blood Pressure in Normotensive Individuals Is More Evident in Women.

BACKGROUND: Considering sex differences, salt sensitivity, and insulin resistance (IR), the effect of sodium restriction and increased potassium intake on blood pressure remains unclear in normotensive Asian individuals, compared to that in hypertensive patients. METHODS: To assess the influence of sodium and potassium intake in normotensive individuals, we evaluated the estimated 24-hour urinary sodium and potassium excretion rate in 3,392 drug-naïve normotensive Japanese individuals (average age: 48.4 years) and analyzed its relation to blood pressure using multivariate regression analysis. RESULTS: Multivariate regression analysis revealed that a 10-mmol/day increment in urinary sodium excretion related to an elevation in systolic blood pressure of 0.16 mm Hg in men and 0.37 mm Hg in women, after adjusting for known risk factors to salt sensitivity, including age, body mass index, serum creatinine, homeostasis model assessment of IR, and urinary potassium excretion. For urinary potassium excretion, a 10-mmol/day increment was associated with a decrease in systolic blood pressure, -0.54 mm Hg in men and -1.49 mm Hg in women, respectively. Furthermore, involvement of IR on blood pressure was observed only in women. CONCLUSIONS: In drug-naïve normotensive individuals, the effects of a lower-salt and higher-potassium diet, and IR on blood pressure, were more evident in women. These results suggest that to prevent the new onset of hypertension and its complications, the balances of a sodium restriction and an increased potassium intake are important even in normotensive individuals, independent of known risk factors for salt sensitivity, especially in women.

Prevalence of Helicobacter pylori infection by birth year and geographic area in Japan.

BACKGROUND: Helicobacter pylori (H. pylori)-related diseases are responsible for a tremendous amount of morbidity and mortality in Japan. We estimated the prevalence of H. pylori infection by sex, birth year, and geographic area among Japanese adults. MATERIALS AND METHODS: This cross-sectional study included 14,716 subjects aged 20 years or more who underwent a health checkup between May 1997 and March 2013 in seven geographic areas throughout Japan. Relevant information on the demographics and status of H. pylori infection was retrieved from the electronic database. The univariate log-binominal regression model was used to estimate the prevalence of H. pylori infection, taking birth year into consideration. The multivariate log-binominal regression model was used to compare the prevalence of H. pylori infection between seven geographic areas. RESULTS: The overall prevalence of H. pylori infection was 37.6% in women and 43.2% in men. Among seven geographic areas, Hokkaido showed the lowest prevalence (29.4%), while Yamagata Prefecture represented the highest (54.5%). The prevalence of H. pylori infection was highest in the 1940-1949 birth cohort and then decreased in the ensuing birth cohorts; the risk ratio (RR) was 0.85 (95% confidence interval (CI) 0.84-0.87) for changes in the 10-year birth cohort. Individuals in Yamagata Prefecture had the highest RR of acquiring H. pylori infection in all three birth cohorts (RR = 1.53 for 1940, RR = 1.69 for 1950, and RR = 1.85 for 1960) when compared with those in Hokkaido. CONCLUSIONS: The prevalence of H. pylori infection increases with age and exhibits geographic variation in Japan. There has been a striking decrease in the prevalence of H. pylori infection, especially in younger Japanese populations.

Prevalence and characteristics of nodular gastritis in Japanese elderly.

BACKGROUND AND AIM: Nodular gastritis (NG) is defined as antral gastritis with endoscopic findings usually characterized by a miliary pattern resembling "goose flesh." There is a possible association between NG and gastric cancer. The aim of our study is to investigate whether there are some differences between young and elderly people in incidence and characteristics of NG and estimate potential risk factors for gastric cancer in adults with NG. METHODS: Patients underwent upper gastrointestinal endoscopy for abdominal symptoms or cancer screening. Incidence rates and relationship between an elderly group (40 years or older) and young group (< 40 years) were assessed by endoscopic grade of NG, atrophic grade, concomitant diseases, and serum pepsinogen (PG). RESULTS: NG was found in 62 cases (0.94%) out of 6623 patients who underwent endoscopy, with a mean age of 47.3 ± 13.3 years. Female patients were present at a significantly higher rate in the elderly group (P < 0.001). The grade of neutrophil infiltration in the greater curvature of the upper gastric body was recognized at a significantly higher rate in the elderly group (P < 0.05). PG II was present at a higher rate and PG I/II at a lower rate in the elderly group (P < 0.05). The odds ratio for the risk of gastric cancer in patients with NG was 2.1 (95% confidence interval 0.3-15.3) in the elderly group. CONCLUSION: NG in the elderly was also suggested to be a risk factor for gastric cancer as well as in the young.

Clinicopathological evaluation of biological behavior of submucosal invasive gastric carcinomas: relationship among lymph node metastasis, mucin phenotype and proliferative activity.

BACKGROUND: Gastric carcinomas have been classified into the differentiated and undifferentiated type, on the basis of its tendency to gland formation. As a result of recent advances in mucin histochemistry, mucin phenotypes of gastric carcinomas have been investigated. However, no consensus on the evaluation of the grade of malignancy of early gastric carcinomas regarding mucin phenotype expression has developed. To address this issue, we evaluated the lymph node metastasis rate and proliferative activity of a submucosal invasive (sm) gastric carcinoma according to mucin phenotype expression. METHODS: In resected surgical specimens from 108 patients with a single sm gastric carcinoma, the association between clinicopathological factors and lymph node metastasis was evaluated. In all cases, immunohistochemical staining with human gastric mucin, Muc-2, and CD10 and mucin histochemical staining by paradoxical concanavalin A staining were performed. The mucin phenotypes were classified into gastric-type (G-type), intestinal-type (I-type), mixed gastric and intestinal type (M-type), or a lack of mucin (LOM), using these as markers. To evaluate the cell proliferative activity of the gastric carcinoma, proliferating cell nuclear antigen (PCNA) staining was also performed. RESULTS: The rate of lymph node metastasis was higher for G-type sm carcinomas. A multivariate analysis showed that the G-type and lymphatic invasion were independent factors of lymph node metastasis. However, the PCNA-labeling index (PCNA-LI) was low for G-type carcinomas irrespective of the presence or absence of lymph node metastasis. In I-type carcinomas, PCNA-LI was significantly higher in cases that were positive for lymph node metastasis than in negative cases. CONCLUSION: G-type and lymphatic invasion are independent risk factors for lymph node metastasis of an sm gastric carcinoma, and proliferative activity may be a significant parameter for lymph node metastasis in cases with I-type carcinomas.

Relationship between lymph node metastasis and E-cadherin expression in submucosal invasive gastric carcinomas with gastric-phenotype.

BACKGROUND: Recent advances in immunohistochemical staining have led to the proposition of a classification of gastric carcinomas based on cellular phenotypes, and the degree of biological malignancy of gastric-phenotype carcinomas has attracted particular attention. SUBJECTS AND METHODS: One hundred and seven submucosal (SM) invasive carcinomas encountered in our center were examined for their histological type, cellular phenotype, and E-cadherin expression status to clarify their relationships with lymph node metastasis. RESULTS: Eleven (10.3%) of 107 SM gastric carcinomas were lymph node metastasis-positive. Gastric-phenotype carcinomas accounted for 20.6%, with a lymph node metastasis rate of 27.3% (6/22), which was significantly higher (p<0.05) than those of intestinal-phenotype carcinomas (5.9%) and mixed-phenotype carcinomas (2.9%). In terms of E-cadherin expression, only carcinomas with reduced E-cadherin expression showed lymph node metastasis at a rate significantly higher than that of carcinomas with normal E-cadherin expression (p<0.05). The lymph node metastasis rate (46.2%) of gastric-phenotype carcinomas with reduced E-cadherin expression was significantly higher than those of carcinomas of other phenotypes (p<0.05). CONCLUSION: Since gastric-phenotype differentiated carcinomas with reduced E-cadherin expression have the potential for becoming undifferentiated, the risk of lymph node metastasis should be considered.