Trends in nutritional intake and coronary risk factors over 60 years among Japanese men in Tanushimaru

Weakened Grip Strength Over 40 Years in a Community-Dwelling Cohort in Tanushimaru, Japan

BACKGROUND

An epidemiological survey has been periodically performed since 1977 among the adult population in Tanushimaru, a typical farming town in Japan. We aimed in this study to retrospectively investigate changes of grip strength (GS) and its correlates over 40 years in the same cohort of community-dwelling adults. We used pooled data from the survey to deduce essential correlates of GS in community-dwelling adults.

METHODS

We retrospectively compared serial correlates of GS in the adult population in Tanushimaru between a population tested in 1977 and 1979 (Cohort A, n=2,452) and another population tested in 2016 and 2018 (Cohort B, n=1,505), to identify essential correlates of GS for investigating changes in GS during the past 40 years in community-dwelling adults.

RESULTS

Age, height, weight, and the occupation of the subjects remained as correlates of GS in both genders during the past 40 years. In males, abdominal circumference also remained as a correlate of GS. Serum albumin levels in males and systolic blood pressure in females were identified as new correlates. GS after adjustment for the above correlates weakened in both genders, and the serial change in GS was particularly remarkable in subjects whose occupations were Class-1 and Class-2, which were defined as moderately hard work.

CONCLUSIONS

From a periodically-performed epidemiological survey of a community-dwelling cohort in a Japanese typical farming town, age, height, weight, and occupation were deduced as essential correlates of GS. GS in the community dwelling cohort weakened in both genders over 40 years, possibly affected by their occupation.

Prognostic risk stratification based on left ventricular mechanical dyssynchrony in patients at low or intermediate risk of major cardiac events using the J-ACCESS risk model

There have been no reports on prognostic prediction and risk stratification based on stress phase bandwidth (SPBW), or a left ventricular (LV) mechanical dyssynchrony index, in patients with known or suspected stable coronary artery disease (CAD) at low or intermediate risk of major cardiac events (MCEs) using the J-ACCESS risk model. We retrospectively investigated 4,996 consecutive patients with known or suspected CAD who underwent rest ²⁰¹Tl and stress ^99mTc-tetrofosmin electrocardiogram (ECG)-gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) and followed up for 3 years to confirm their prognosis. MCE risk over 3 years was estimated using an equation based on that used in the J-ACCESS study. The composite endpoint was the onset of MCEs consisting of cardiac death, non-fatal myocardial infarction (MI), and severe heart failure requiring hospitalization. SPBW was calculated by phase analysis with the Heart Risk View-F software and its normal upper limit was set to 38°. Based on the estimated 3-year incidence of MCEs obtained from the J-ACCESS risk model, 4,123 of the 4,996 consecutive patients were classified as low (n = 2,653) or intermediate risk (n = 1,470) and they were analyzed for follow-up. During the follow-up, 153 patients experienced MCEs: cardiac death (n = 38), non-fatal MI (n = 45), and severe heart failure (n = 70). The results of the multivariate analysis showed age, estimated glomerular filtration rate (eGFR), stress LV ejection fraction, and stress SPBW to be independent predictors of MCEs. The actual 3-year MCE rate in patients at intermediate risk was significantly higher than in those at low risk (6.7% vs. 2.1%, P < 0.0001). However, the actual 3-year MCE rate in patients with abnormal SPBW (> 38°) was 4.0% and 9.2% in low- and intermediate-risk patients, respectively, which corresponded to intermediate and high risk. Kaplan-Meier analysis also showed significant risk stratification by normal SPBW values for both low- and intermediate-risk patients. LV mechanical dyssynchrony assessed with ECG-gated SPECT MPI is useful for risk stratification of known or suspected stable CAD patients at low or intermediate risk of MCEs and may help identify higher risk patients who could not be identified as being at risk based on J-ACCESS risk assessment.

History of cardiovascular epidemiology in Japan

There are several patterns of epidemiological study in Japan. One is the international collaborative studies, such as Seven Countries Study, NI-HON-SAN Study, International Study of Salt and Blood Pressure (INTERSALT), International Study of Macro-and Micro-nutrients and Blood Pressure (INTERMAP), and Monitoring of Cardiovascular Disease (MONICA). The next one is the several cohort studies in Japanese unique surveys, such as Hisayama Study, Osaka-Akita Study, Tanno-Sobetsu Study, Suita Study, Ohazama Study, National Integrated Project for Prospective Observation of Noncommunicable Disease and Its Trends in the Aged (NIPPON DATA), Japan Collaborative Cohort (JACC), and Japan Public Health Center-Based Study (JPHC). Finally, some recent special meta-analysis in Japan are Japan Arteriosclerosis Longitudinal Study (JALS) and Evidence for Cardio-vascular Prevention from Observational Cohorts in Japan (EPOCH-JAPAN). The aim of this review is to introduce the history of epidemiologcal study, especially, cardiovascular epidemiology from the mid-20th century to in the early 21st century by dividing three patterns.

Dietary Transitions and Health Outcomes in Four Populations - Systematic Review

IMPORTANCE

Non-communicable chronic diseases (NCDs) such as obesity, type 2 diabetes, heart disease, and cancer were rare among non-western populations with traditional diets and lifestyles. As populations transitioned toward industrialized diets and lifestyles, NCDs developed.

OBJECTIVE

We performed a systematic literature review to examine the effects of diet and lifestyle transitions on NCDs.

EVIDENCE REVIEW

We identified 22 populations that underwent a nutrition transition, eleven of which had sufficient data. Of these, we chose four populations with diverse geographies, diets and lifestyles who underwent a dietary and lifestyle transition and explored the relationship between dietary changes and health outcomes. We excluded populations with features overlapping with selected populations or with complicating factors such as inadequate data, subgroups, and different study methodologies over different periods. The selected populations were Yemenite Jews, Tokelauans, Tanushimaru Japanese, and Maasai. We also review transition data from seven excluded populations (Pima, Navajo, Aboriginal Australians, South African Natal Indians and Zulu speakers, Inuit, and Hadza) to assess for bias.

FINDINGS

The three groups that replaced saturated fats (SFA) from animal (Yemenite Jews, Maasai) or plants (Tokelau) with refined carbohydrates had negative health outcomes (e.g., increased obesity, diabetes, heart disease). Yemenites reduced SFA consumption by >40% post-transition but men's BMI increased 19% and diabetes increased ~40-fold. Tokelauans reduced fat, dramatically reduced SFA, and increased sugar intake: obesity and diabetes rose. The Tanushimaruans transitioned to more fats and less carbohydrates and used more anti-hypertensive medications; stroke and breast cancer declined while heart disease was stable. The Maasai transitioned to lower fat, SFA and higher carbohydrates and had increased BMI and diabetes. Similar patterns were observed in the seven other populations.

CONCLUSION

The nutrient category most strongly associated with negative health outcomes - especially obesity and diabetes - was sugar (increased 600-650% in Yemenite Jews and Tokelauans) and refined carbohydrates (among Maasai, total carbohydrates increased 39% in men and 362% in women), while increased calories was less strongly associated with these disorders. Across 11 populations, NCDs were associated with increased refined carbohydrates more than increased calories, reduced activity or other factors, but cannot be attributed to SFA or total fat consumption.

Differential impacts of 24 hour urinary sodium excretion on cardiovascular diseases or cancer mortality in a general population

BACKGROUND

Elevated blood pressure is a major risk factor for cardiovascular (CV) disease. But the effects of sodium intake or excretion on CV mortality are uncertain. The present study aimed to investigate the association between 24 h urinary sodium excretion, as a marker of dietary salt intake, and CV or cancer mortality in a healthy Japanese population using 24 hurine collection.

METHODS

The baseline study was conducted in 1980. A total of 1291 participants aged 21 to 85 years, underwent health check-ups, which included blood chemistry measurements and the collection of 24 h urine samples. Enrolled 1291 participants were followed up for 27.5 years, in whom the final follow-up rate was 95.8%. Cox proportional hazards regression models were used to assess the association between 24 h urinary sodium excretion and CV or cancer mortality.

RESULTS

The mean 24 h urinary sodium excretion was 5.80 ± 2.28 g/day. There were 631 deaths: 153 (27%) from cancer, 142 (26%) from CV disease. In the Cox proportional hazard regression model after adjustment for confounding factors, systolic and diastolic blood pressures, and uric acid were positively associated with CV mortality, and the 24 h urinary sodium and potassium excretions were inversely associated with CV mortality (p < 0.05). On the other hand, there were no association between 24 h urinary sodium excretions and cancer mortality. We divided the urinary sodium excretions levels into quartiles. After adjustment for confounding factors, the hazard ratio of CV mortality in the highest quartile of 24 h urinary sodium excretion versus the lowest was 0.46 (p < 0.05). The cumulative survival rate for CV death was significantly decreased in the lowest quartile compared with the other higher groups.

CONCLUSIONS

We found that impacts of 24 h sodium excretion on CV and cancer mortalities were much different in the general population.

Dietary fatty acids and CHD: from specific recommendations to dietary patterns

Several countries have issued dietary recommendations about total and specific fatty acid (FA) intake for the prevention of CHD. For many years until today, controversies have existed especially about the deleterious effect or not of SFA, and the protective effect or not of n-3 PUFA, so that some authors have criticised these recommendations. There are many reasons for these controversies, including the different conclusions of prospective cohort studies compared with randomised clinical trials (RCT), and the contradictory conclusions of meta-analyses depending on the quality, number and type of studies included. The interrelationships between different FA in the diet make it difficult to analyse the specific effect of a particular class of FA on CHD. Furthermore, based on clinical practice and effectiveness of population-based prevention, it is very difficult at the individual level to assess in personal dietary intake the actual percentage and/or amount of SFA contained in each meal or consumed daily/weekly. In this critical narrative review, we try to answer the question of whether it would not be more relevant, in 2020, to promote dietary patterns, rather than FA intake recommendations. We critically analyse past and recent data on the association of FA with CHD, then propose that the Mediterranean diet and Japanese diet should be revitalised for Westerners and Asian populations, respectively. This does not exclude the usefulness of continuing research about effects of FA towards CHD, and accepting that what seems true today might be revised, at least partially tomorrow.