Validation of improved 24-hour dietary recall using a portable camera among the Japanese population.

BACKGROUND: The collection of weighed food records (WFR) is a gold standard for dietary assessment. We propose using the 24-h recall method combined with a portable camera and a food atlas (24hR-camera). This combination overcomes the disadvantages of the 24-h dietary recall method. Our study examined the validity of the 24hR-camera method against WFR by comparing the results. METHODS: Study subjects were 30 Japanese males, aged 31-58 years, who rarely cook and reside in the Tokyo metropolitan area. For validation, we compared the estimated food intake (24hR-camera method) and weighed food intake (WFR method). The 24hR-camera method uses digital photographs of all food consumed during a day, taken by the subjects, and a 24-h recall questionnaire conducted by a registered dietitian, who estimates food intake by comparing the participant's photographs with food atlas photographs. The WFR method involves a registered dietitian weighing each food item prepared for the subject to consume and any leftovers. Food intake was calculated for each food group and nutrient using the 24hR-camera vs. weighed methods. RESULTS: Correlation coefficients between the estimated vs. weighed food intake were 0.7 or higher in most food groups but were low in food groups, such as oils, fats, condiments, and spices. The estimated intake of vegetables was significantly lower for the 24hR-camera method compared to the WFR method. For other food groups, the percentages of the mean difference between estimated vs. weighed food intake were -22.1% to 5.5%, with no significant differences between the methods (except for algae, which had a very low estimated intake). The correlation coefficients between the two methods were 0.774 for energy, and 0.855, 0.769, and 0.763 for the macronutrients, proteins, lipids, and carbohydrates, respectively, demonstrating high correlation coefficients: greater than 0.75. The correlation coefficients between the estimated vs. weighed for salt equivalents and potassium intake were 0.583 and 0.560, respectively, but no significant differences in intake were observed. CONCLUSIONS: The 24hR-camera method satisfactorily estimated the intake of energy and macronutrients (except salt equivalents and potassium) in Japanese males and was confirmed as a useful method for dietary assessment.

Impact of serum uric acid on renal function and cardiovascular events in hypertensive patients treated with losartan.

High serum uric acid level (SUA) and chronic kidney disease (CKD) are risk factors for cardiovascular events (CVEs). However, their interactions as cardiovascular risk factors remain unknown. This subanalysis of the Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH) study included 7629 patients, in whom the serum creatinine level was measured at least twice. The study examined the impact of hyperuricemia (SUA ≥7 mg dl(-1)) on CVE according to the level of renal dysfunction and whether early changes in SUA predicted future glomerular filtration rates (GFRs). The mean follow-up period was 3.1 years. The patients were divided into three groups according to the baseline estimated GFR (eGFR): groups A, B and C with eGFR <45, 45-59 and ≥60 ml min(-1) per 1.73 m(2), respectively. eGFR increased from 38.1 to 57.6, from 52.8 to 67.5 and from 74.7 to 80.7 ml min(-1) per 1.73 m(2) in groups A, B and C, respectively. In non-hyperuricemic patients, the CVE rate was 10.83, 4.98 and 4.21/1000 person-years in groups A, B and C, respectively, while in hyperuricemic patients, the corresponding values were 14.18, 17.02 and 5.93. Thus, hyperuricemia increased the risk of CVE only in group B (relative risk (RR) 3.43 (95% confidence interval (CI) 1.55 to 7.60); P<0.002). The final change in the eGFR was negatively correlated with the change in SUA from baseline to year 1 (P<0.001). CVEs were more frequent in those with a decrease in eGFR. Hyperuricemia may be a major determinant of increased cardiovascular risk in CKD stage 3A, and SUA may be involved in the progression of CKD. Changes in the GFR influence the rate of CVE.

The importance of home blood pressure measurement for preventing stroke and cardiovascular disease in hypertensive patients: a sub-analysis of the Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH) study, a prospective nationwide observational study.

White-coat hypertension (HT) and masked HT can be identified by home blood pressure (BP) measurement. The prevalence of these subtypes and the associated risk of cardiovascular disease have not been fully investigated among Japanese hypertensive patients. The risk of cardiovascular events due to HT and its relationship with home BP measurement were examined among Japanese hypertensive patients receiving treatment in the Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH) study, a nationwide prospective observational study. Both home and clinic BP were measured during treatment, and the occurrence of cardiovascular events was monitored in 4,596 Japanese patients (mean age of 60.8 years, 43.2% men, and mean follow-up period of 3.5 years). HT was defined as a systolic BP > or =140 mmHg for clinic BP and > or =135 mmHg for home BP while on treatment. The relative risk of all cardiovascular events and stroke increased along with higher clinic and home BP levels during treatment. The prevalence of white-coat HT, masked HT, well-controlled HT, and poorly controlled HT was 12.6%, 19.5%, 23.8%, and 44.1%, respectively. The relative risk of cardiovascular events was not significantly increased in the poorly controlled HT (relative risk [RR]: 2.05, 95% confidence interval [CI]: 0.77-5.45), white-coat HT (RR: 0.77, 95% CI: 0.15-3.96), and masked HT (RR: 2.00, 95% CI: 0.67-5.98) subgroups compared with the well-controlled-HT subgroup; however, the risk of masked HT was similar to that of poorly controlled HT. Monitoring both clinic and home BP is important to diagnose masked HT and to prevent cardiovascular disease in this subtype of HT. However, further investigation is required to fully characterize the cardiovascular risks associated with masked HT among Japanese patients receiving treatment.

FokI variant of vitamin D receptor gene and factors related to atherosclerosis associated with ossification of the posterior longitudinal ligament of the spine: a multi-hospital case-control study.

STUDY DESIGN: A sex- and age-matched case-control study with genotyping of the FokI variant of the vitamin D receptor gene (VDR) was carried out. OBJECTIVES: To facilitate the early prediction, prevention, and treatment of ossification of the posterior longitudinal ligament (OPLL) of the spine, we analyzed the FokI variant of VDR and past body mass indexes, histories of past illness, family history, and body pliability along with lifestyle factors. SUMMARY OF BACKGROUND DATA: Many possible genetic and environmental risk factors for OPLL have been suggested, including male sex, high body mass index, diabetes mellitus, trauma, hormonal imbalance, and dietary and sleeping habits and genetic variants. METHODS: Both a self-administered questionnaire and whole blood samples were obtained from 63 patients with OPLL and 126 sex-, age-, and hospital-matched controls free of backbone diseases were randomly selected from hospital patients. VDR genotyping was carried out using PCR-RFLP methods. After univariate analysis, multivariate and subgroup analyses according to the VDR genotype was applied to clarify the confounding relationship between VDR genotype and other possible risk factors. RESULTS: A multivariate analysis revealed that the VDR FF genotype, family history of myocardial infarction, high body mass index at age 40, long working hours, and working with night shift to be independent potent risk factors for OPLL. CONCLUSION: The risk of developing OPLL may possibly be reduced gradually and effectively by removing or minimizing the effect of such lifestyle factors one at a time through targeted preventive intervention.

Impact of blood pressure control on cardiovascular events in 26,512 Japanese hypertensive patients: the Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH) study, a prospective nationwide observational study.

The Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH) study was performed to investigate the relationship between blood pressure (BP) and development of stroke or myocardial infarction (MI) in Japanese hypertensive patients. A total of 26,512 hypertensive patients (mean age: 62.2 years, 43.9% men) were analyzed. All patients received open-labelled losartan for a maximum of 5 years. Endpoints were stroke, MI including sudden cardiac death, and all cardiovascular (CV) events (stroke and MI). The mean observation period was 3.0 years. The mean baseline systolic/diastolic BP was 165.8/94.8 mmHg and decreased to 141.6/82.0 mmHg during treatment. The incidences of stroke, MI, and total CV events were 3.90, 1.02, and 4.92 per 1,000 patient-years, respectively. Aging, diabetes, a history of CV disease, and smoking were independent risk factors for CV events. The risk of all CV events was positively related to BP level during treatment, and increased significantly when the BP exceeded 140/90 mmHg. Age was a strong contributor to CV events, but about a half of the very elderly patients (>or=85 years, n=692) had a BP below 140/90 mmHg during treatment and significantly fewer events occurred in these patients than in those with a BP of 140/90 mmHg or higher. These results suggest that BP should be below 140/90 mmHg in Japanese patients with hypertension for reducing the risk of CV events. BP was controlled below 140/90 mmHg in a half of the very elderly hypertensive patients in this study, and these patients also had a lower incidence of CV events.

Efficacy and safety of long-term losartan therapy demonstrated by a prospective observational study in Japanese patients with hypertension: The Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH) study.

The Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH) study is a nationwide, prospective, multicentered, observational study that was designed to enroll 30,000 hypertensive Japanese patients from more than 3,000 private practitioners. It is the first large-scale observational study to assess the efficacy and safety of losartan, an angiotensin II receptor antagonist, in Japan. Patients were enrolled between June 2000 and May 2002, and followed up to June 2005. The data from 29,850 patients were used for the analysis of safety and efficacy. These patients were treated with losartan mostly at a daily dose of 25-50 mg. The mean follow-up period was 2.9 years. The patients were aged 62.4+/-12.1 years (mean+/-SD) and their mean systolic/diastolic blood pressure was 165.3+/-17.2/94.3+/-11.7 mmHg (mean+/-SD). Mean blood pressure in patients who were evaluated for efficacy decreased from 165.8/94.8 mmHg (n=26,512) at baseline to 145.5/84.4 mmHg after 3 months (n=21,269) and 138.6/80.0 mmHg after 36 months of treatment (n=13,879). Blood pressure was well controlled during the study period by losartan alone or losartan-based combination therapy. In nearly half of the patients, blood pressure was reduced to less than 140/90 mmHg during the study period. In addition to its antihypertensive effect, losartan reduced the uric acid level in patients whose baseline uric acid level was > or =7 mg/dL. Losartan also prevented acceleration of proteinuria. Adverse drug reactions occurred in 1,081 of the 29,850 patients. Long-term losartan therapy was effective and well tolerated in Japanese clinical practice.

Design and baseline characteristics of an observational study in Japanese patients with hypertension: Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH).

The Japan Hypertension Evaluation with Angiotensin II Antagonist Losartan Therapy (J-HEALTH) study is a nationwide, prospective, multicenter observational study that was designed to enroll hypertensive Japanese patients (>30,000 subjects). The patients in this study received treatment with open-label losartan, an angiotensin II receptor antagonist, for a maximum of 5 years. This report summarizes the study protocol and the baseline characteristics of the patients. Between June 2000 and May 2002, patients were screened in all 47 prefectures around Japan. Among the 31,515 patients screened, 31,048 patients were enrolled in this study and treated with losartan at a daily dose of 25-50 mg. These patients were 62.4 +/- 12.1 years old (mean +/- SD) and the mean clinic systolic/diastolic blood pressure (BP) values were 165.3 +/- 17.3/94.3 +/- 11.7 mmHg (mean +/- SD). The complications of hyperlipidemia, diabetes mellitus, cardiovascular disease, and cerebrovascular disease were also present in 38.5%, 13.1%, 8.0%, and 4.4% of patients, respectively. Regarding the World Health Organization classification, grade 2 hypertension was most frequent in this patient cohort. Nearly 10,000 patients agreed to perform home BP monitoring and report details regarding their lifestyles at baseline. Among the patients, 4.2% had white coat hypertension at the baseline. The J-HEALTH study is expected to provide valuable information about the significance of clinic and home BP control and home BP monitoring for the management of hypertension in Japanese patients.

Gly395Arg polymorphism of PPARalpha gene was not detected in Japanese population of 729 individuals.

Peroxisome proliferator-activated receptor a (PPARalpha) is a member of the nuclear receptor superfamily and participates in the regulation of key proteins involved in lipid metabolism, fatty acid oxidation, homeostasis, and inflammation. Several polymorphisms of the human PPARalpha gene, such as Leu162Val polymorphism and Val227Ala polymorphism, have been described in different races. Recently, another PPARalpha polymorphism Gly395Arg polymorphism has been reported in Caucasian and African subjects. Using the Invader assay, we searched for this polymorphism in 729 Japanese adults randomly selected in a rural population. Although the synthesized oligonucleotides of each polymorphism could be distinguished clearly, all 729 individuals had the Gly (G) allele and none had the Arg (C) allele. These data suggest that there is racial variability in the frequencies of PPARalpha gene polymorphisms.

Polymorphism of methylenetetrahydrofolate reductase gene (C677T MTHFR) is not a confounding factor of the relationship between serum uric acid level and the prevalence of hypertension in Japanese men.

BACKGROUND: The association between serum uric acid (UA) and the prevalence of hypertension, and the relationship between methylenetetrahydrofolate reductase (MTHFR) polymorphism and hypertension remains unclear. The aim of the present study was to investigate whether the C677T MTHFR mutation genotype (VV) is independently associated with the prevalence of hypertension or blood pressure (BP), and examined any interaction of MTHFR and UA with BP. METHODS AND RESULTS: Participants were randomly selected from all residents (aged 40-69 years) in a rural county of Japan, and the data for the men (n=335) were analyzed. ;Hypertension' was defined as systolic BP >or=140 and/or diastolic BP >or=90 mmHg and/or being administered antihypertensive medication. Serum UA level was independently associated with the prevalence of hypertension (odds ratio (95% confidence interval) =2.7 (1.2-5.9), p=0.047) for the highest tertile of serum UA (>or=398.5 micromol/L (6.7 mg/dl)) vs that of the lowest tertile (<321.2 micromol/L (5.4 mg/dl)), but the MTHFR mutation was not independently associated with prevalence of hypertension or BP. No interaction of the MTHFR mutation and serum UA with BP was found. CONCLUSIONS: The mutation of C677T MTHFR was not independently associated with the prevalence of hypertension or BP levels although serum UA was. Furthermore, the relationship between serum UA and BP was not modulated by the MTHFR mutation in Japanese men.

The 2.3 genotype of ESRRA23 of the ERR alpha gene is associated with a higher BMI than the 2.2 genotype.

ERR alpha (NR3B1) is an orphan nuclear receptor believed to be involved in energy metabolism and obesity. A 23-base pair sequence in the 5'-flanking region of the ERR alpha gene, referred to as ESRRA23, is polymorphic in human chromosomes. Here, we investigated the influence of the ESRRA23 polymorphism on obesity in 703 Japanese individuals by analyzing indices of obesity and related lifestyle factors. The frequency of genotypes was similar to that reported in whites. The 2.3-genotype was associated with a significantly higher BMI than was the 2.2-genotype. An increased number of ESRRA23 repeats may be a genetic factor in human obesity.

Case-control study of medical history and idiopathic pulmonary fibrosis in Japan.

OBJECTIVES: A few epidemiological studies have indicated that a patient's past medical history may contribute to the risk of developing idiopathic pulmonary fibrosis (IPF). A relationship between a history of selected disorders and the risk of IPF was assessed in a multicentre hospital-based case-control study in Japan. METHODOLOGY: Included in the study were 104 patients of IPF, aged 40 years or over, who had been diagnosed within the previous 2 years, in accordance with the most recent criteria. Control subjects, aged 40 years or over, consisted of 56 hospitalized patients diagnosed as having acute bacterial pneumonia and four outpatients with the common cold. Adjustment was made for age, gender, region, pack-years of smoking, employment status, occupational exposure and BMI. RESULTS: Medical histories of hypertension, hyperlipidaemia, coronary heart disease, diabetes mellitus, hepatitis C virus infection, tuberculosis, asthma, atopic dermatitis and allergic rhinitis were not statistically significantly associated with the risk of IPF, although cases were more likely to have suffered from allergic rhinitis and less likely to have been asthmatics than control subjects. Having a child with a history of allergic rhinitis, but not of asthma or atopic dermatitis, was significantly related to an increased risk of IPF. CONCLUSIONS: These findings suggest that a genetic predisposition to allergic rhinitis may be associated with an increased risk of IPF.

Epidemiological evidence that acetaldehyde plays a significant role in the development of decreased serum folate concentration and elevated mean corpuscular volume in alcohol drinkers.

BACKGROUND: Elevated mean corpuscular volume (MCV) is a traditional biological marker for alcohol abuse and alcoholism, but the underlying mechanism is unclear. Three recent epidemiologic studies consistently showed that MCV was elevated by alcohol drinking more markedly among individuals with genetically inactive aldehyde dehydrogenase-2 (ALDH2) (encoded by ALDH2*2 mutant allele) than those with active ALDH2 (encoded by ALDH2*1/2*1 genotype), suggesting that the elevated MCV was etiologically linked to acetaldehyde exposure. The purpose of the present study was to clarify further this relationship by examining the status of folate and vitamin B12. METHODS: The study participants were 159 men who were aged 40 to 69 years and randomly selected from a Japanese rural population. The genetic polymorphism of ALDH2 was determined by PCR-restriction fragment length polymorphism method; data on alcohol drinking and other lifestyles were collected using a structured questionnaire; serum concentrations of folate and vitamin B12 were measured using the protein competitive reaction method, and blood cell counts were measured by routine methods. A multiple linear regression model was used to analyze the data. RESULTS: : The relationship between alcohol drinking and serum folate concentration was significantly different between ALDH2 genotypes, indicating that the reduction of serum folate by alcohol drinking was more marked in men with ALDH2*1/2*2 than those with ALDH2*1/2*1. The relationship between alcohol drinking and elevated MCV was significantly stronger in men with ALDH2*1/2*2 than those with ALDH2*1/2*1 even after adjustment for serum folate and vitamin B12 concentrations. CONCLUSIONS: These findings indicate that acetaldehyde plays a significant role in the development of decreased serum folate concentration and elevated MCV by alcohol drinking.

The relationships between plasma total homocysteine and selected atherosclerotic risk factors according to the C677T methylenetetrahydrofolate reductase gene in Japanese.

BACKGROUND: Variation of plasma total homocysteine (tHcy) levels among individuals is modified by 5,10-methylenetetrahydrofolate reductase (MTHFR) genotypes and selected atherosclerotic risk factors. DESIGN: Cross-sectional study. METHODS: Healthy Japanese men (n=213) and women (n=242) aged 40-69 years were examined. RESULTS: Serum uric acid, hemoglobin, hematocrit, serum creatinine, and men were independently significantly associated with plasma tHcy. The relationship between serum uric acid and plasma tHcy was the strongest in those with the mutant homozygote (VV), but the overall statistical test of interaction was not significant. CONCLUSIONS: Serum uric acid, hematocrit, hemoglobin, creatinine, and men were determinants of plasma tHcy levels. Further investigations are needed.

Descriptive epidemiology of amyotrophic lateral sclerosis in Japan, 1995-2001.

BACKGROUND: This study was conducted to describe the epidemiologic features of amyotrophic lateral sclerosis (ALS) in Japan by examining annual trends in mortality (1995-2001), and to discuss the background factors possibly responsible for the recent variations in the mortality rate. METHODS: Trends in both the age-adjusted and age-specific mortality rates of ALS were examined by using the data obtained from the vital statistics of Japan between 1995 and 2001. RESULTS: There were small increases in the number of ALS deaths (from 1249 to 1400 per year) and the crude mortality rates (from 1.00 to 1.10 per 100,000 population) between 1995 and 2001. The age-adjusted mortality rate of ALS (adjusted using the 1985 model population of Japan) has decreased (from 0.84 per 100,000 population in 1995 to 0.74 in 2001). Age-specific mortality rates have been increasing particularly in the population older than 70 years of age, with the peak in mortality in the 70- to 80-year old age group. CONCLUSIONS: ALS mortality rates increased proportionally more for elderly population during the study period. Further epidemiologic studies will be needed to clarify the possible background factors contributing to the increase in ALS mortality in the elderly.

Relationship between the ability to recognize energy intake and expenditure, and blood sugar control in type 2 diabetes mellitus patients.

To investigate the association between an individual's ability to recognize his/her energy intake and energy expenditure with the status of diabetes mellitus (DM) control, we conducted a cross-sectional study using data from 62 outpatients with type 2 DM (46 men and 16 women), aged 33-77 years, from two hospitals in Tokyo in 1999. A dietitian-interviewer asked the patients to estimate their probable energy intake and expenditure in recent days (self-estimated energy intake and expenditure, respectively). Subsequently, a dietary survey was conducted to estimate the patient's energy intake by a self-recorded method with a dietitian's interview for three continuous business days; the physical exercise levels were measured using a pedometer with multiple-memory accelerometers for one week. The percentage of subjects whose self-estimated energy intake was within +/-10% of the dietary survey-based energy intake became significantly lower as the control status worsened (35.6, 12.9, and 11.1% in the first, second, and third tertile groups of HbA(1c), respectively; P = 0.015). Similar but non-significant results were observed for the energy expenditure (P = 0.35). Since the control status of DM was worse among patients who could not recognize their amount of caloric intake and expenditure, a training program to improve such recognition ability may be needed.

Dietary risk factors for inflammatory bowel disease: a multicenter case-control study in Japan.

To evaluate the role of dietary factors in the etiology of inflammatory bowel disease (IBD), we conducted a multicenter hospital-based case-control study in a Japanese population. Cases were IBD patients aged 15 to 34 years [ulcerative colitis (UC) 111 patients; Crohn's disease (CD) 128 patients] within 3 years after diagnosis in 13 hospitals. One control subject was recruited for each case who was matched for sex, age, and hospital. A semiquantitative food frequency questionnaire was used to estimate preillness intakes of food groups and nutrients. All the available control subjects (n = 219) were pooled, and unconditional logistic models were applied to calculate odds ratios (ORs). In the food groups, a higher consumption of sweets was positively associated with UC risk [OR for the highest versus lowest quartile, 2.86; 95% confidence interval (CI), 1.24 to 6.57], whereas the consumption of sugars and sweeteners (OR, 2.12; 95% CI, 1.08 to 4.17), sweets (OR, 2.83; 95% CI, 1.38 to 5.83), fats and oils (OR, 2.64; 95% CI, 1.29 to 5.39), and fish and shellfish (OR, 2.41; 95% CI, 1.18-4.89) were positively associated with CD risk. In respect to nutrients, the intake of vitamin C (OR, 0.45; 95% CI, 0.21 to 0.99) was negatively related to UC risk, while the intake of total fat (OR, 2.86; 95% CI, 1.39 to 5.90), monounsaturated fatty acids (OR, 2.49; 95% CI, 1.23 to 5.03) and polyunsaturated fatty acids (OR, 2.31; 95% CI, 1.12 to 4.79), vitamin E (OR, 3.23; 95% CI, 1.45 to 7.17), and n-3 (OR, 3.24; 95% CI, 1.52 to 6.88) and n-6 fatty acids (OR, 2.57; 95% CI, 1.24 to 5.32) was positively associated with CD risk. Although this study suffers from the shortcoming of recall bias, which is inherent in most retrospective studies (prospective studies are warranted to confirm the associations between diet and IBD risk), the present findings suggest the importance of dietary factors for IBD prevention.

Occupational and environmental factors and idiopathic pulmonary fibrosis in Japan.

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing interstitial lung disease of unknown etiology. Environmental factors, especially occupational agents, may be of great importance in the manifestation of IPF. We examined the relationship between occupational and environmental factors and IPF in Japan. A multicenter hospital-based case-control study was performed in 2001. Included were 102 cases aged 40 years or over who were within 2 years of having been diagnosed in accordance with the most recent criteria. Controls, aged 40 years or over, were 55 hospitalized patients diagnosed as having acute bacterial pneumonia and four outpatients with common colds. Data on occupational and environmental factors were obtained from a questionnaire. Multiple logistic regression analysis was used to estimate the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of IPF for single factors with adjustment for age, sex and region. Compared with controls, cases were more likely to have been managers, officials or production workers and less likely to have been protective service or materials handling workers. Clerical and related work was significantly related to a decreased risk of IPF after further adjustment for pack-years of smoking (OR = 0.42; 95% CI = 0.18-0.95). Exposure to metal dust was significantly associated with an increased risk of IPF (OR = 9.55; 95% CI = 1.68-181.12). From 20.0 to 39.9 pack-years of smoking was significantly associated with an increased risk of IPF (OR = 3.23; 95% CI = 1.01-10.84). Our results appear to confirm data from previous epidemiologic studies. Metal dust exposure may be a particularly important risk factor for IPF.

Vegetable, fruit, and cereal intake and risk of idiopathic pulmonary fibrosis in Japan.

AIMS: There has been little interest in the role of nutrition in prevention of idiopathic pulmonary fibrosis (IPF). We investigated the relationship between dietary intake of vegetables, fruit, cereals, antioxidants, and fiber and the risk of IPF in Japan. METHODS: Included were 104 cases aged 40 years or over who were within 2 years of the diagnosis in accordance with the most recent criteria. Controls aged 40 years or over comprised 56 hospitalized patients diagnosed as having acute bacterial pneumonia and 4 outpatients with common cold. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for age, sex, region, pack-years of smoking, employment status, occupational exposure, saturated fatty acid intake, and body mass index. RESULTS: Consumption of fruit in the second and third quartiles was associated with a statistically significant reduced risk of IPF. Although not statistically significant, a beneficial association between soluble fiber intake and IPF was found. No statistically significant dose-response relationship was observed between intake of green and yellow vegetables, other vegetables, cereals, beta-carotene, vitamins C and E, or insoluble fiber and the risk of IPF. CONCLUSION: Our findings suggest that fruit intake may confer protection against the development of IPF.