Dietary sodium intake is associated with long-term risk of new-onset atrial fibrillation.

BACKGROUND: The association between dietary salt intake and hypertension has been well documented. We evaluated the association between dietary sodium intake and the incidence of new-onset atrial fibrillation (AF) during a mean follow-up of 19 years among 716 subjects from the Oulu Project Elucidating Risk of Atherosclerosis (OPERA) cohort. MATERIAL AND METHODS: Dietary sodium intake was evaluated from a seven-day food record. The diagnosis of AF (atrial flutter included) was made if ICD-10 code I48 was listed in the hospital discharge records during follow-up. RESULTS: In the Kaplan-Meier curves, when quartiles of sodium consumption were considered, the cumulative proportional probabilities for AF events were higher in the highest (4th) quartile (16.8%) than in the lower quartiles (1st 6.7%, 2nd 7.3% and 3rd 10.6%) (p = .003). In the Cox regression analysis, sodium consumption (g/1000 kcal) as a continuous variable was independently associated with AF events (Hazard Ratio = 2.1 (95% CI, 1.2 to 3.7) p =.015) when age, body mass index, smoking (pack-years), office systolic blood pressure, left atrium diameter, left ventricular mass index and the use of any antihypertensive therapy were added as covariates. CONCLUSIONS: These findings indicate that sodium intake is associated with the long-term risk of new-onset AF. Further confirmatory studies are needed. Key messages Sodium consumption correlated positively with CV risk factors: age, smoking, SBP, BMI and LDL-cholesterol. When quartiles of sodium consumption were considered, the AF incidence was higher in the highest quartile compared to lower quartiles. Sodium consumption as a continuous variable was independently associated with AF events when age, BMI, smoking, SBP, LAD, LVMI and the use of any antihypertensive therapy were considered.

Increased daily sodium intake is an independent dietary indicator of the metabolic syndrome in middle-aged subjects.

AIMS: We investigated the association between daily sodium intake and each individual component of the metabolic syndrome (MS) as well as the metabolic cluster per se and clarified which of the combinations of MS features is particularly associated with sodium intake. METHODS: A total of 716 subjects from our OPERA (Oulu Project Elucidating Risk of Atherosclerosis) cohort were selected to fill in a food follow-up diary for a 1-week period. The MS was determined using the International Diabetes Federation (IDF) criteria. RESULTS: Subjects with the MS used more sodium (P < 0.001), less carbohydrate (P < 0.001), less fibre (P = 0.031), and more alcohol (P < 0.001) than those without the MS. High sodium intake was strongly related to elevated BMI (P = 0.003), waist (P < 0.001), and higher fasting blood glucose (P < 0.001). The subjects with the highest sodium intake suffered more often from type 2 diabetes (P = 0.007). Sodium intake was highest in the group where all the MS criteria were present (P < 0.001). High sodium intake was a statistically significant predictor of the MS in logistic regression analysis (P = 0.009). The highest sodium intake was observed in the IDF criteria combination waist + glucose + blood pressure. CONCLUSIONS: These findings suggest that a reduction in sodium intake may be especially beneficial in the treatment of individuals with the MS.

Tomato juice decreases LDL cholesterol levels and increases LDL resistance to oxidation.

High dietary intakes of tomato products are often associated with a reduced risk of CVD, but the atheroprotective mechanisms have not been established. This study was conducted to investigate the effects of increased dietary intake of tomato products on plasma lipids and LDL oxidation. The diet intervention included a baseline period, a 3-week low tomato diet (no tomato products allowed) and a 3-week high tomato diet (400 ml tomato juice and 30 mg tomato ketchup daily). Twenty-one healthy study subjects participated in the study. Total cholesterol concentration was reduced by 5.9 (sd 10) % (P = 0.002) and LDL cholesterol concentration by 12.9 (sd 17.0) % (P = 0.0002) with the high tomato diet compared to the low tomato diet. The changes in total and LDL cholesterol concentrations correlated significantly with the changes in serum lycopene (r 0.56, P = 0.009; r 0.60, P = 0.004, total and LDL, respectively), beta-carotene (r 0.58, P = 0.005; r 0.70, P < 0.001) and gamma-carotene concentrations (r 0.64, P = 0.002; r 0.64, P = 0.002). The level of circulating LDL to resist formation of oxidized phospholipids increased 13 % (P = 0.02) in response to the high tomato diet. In conclusion, a high dietary intake of tomato products had atheroprotective effects, it significantly reduced LDL cholesterol levels, and increased LDL resistance to oxidation in healthy normocholesterolaemic adults. These atheroprotective features associated with changes in serum lycopene, beta-carotene and gamma-carotene levels.

Changes in dietary fat intake alter plasma levels of oxidized low-density lipoprotein and lipoprotein(a).

OBJECTIVE: To assess the effects of dietary modifications on oxidized low-density lipoprotein (LDL). METHODS AND RESULTS: Thirty-seven healthy women were fed two diets. Both diets contained a reduced amount of total and saturated fat. In addition, one diet was low in vegetables and the other was high in vegetables, berries, and fruit. The dietary intake of total fat was 70 g per day at baseline and decreased to 56 g (low-fat, low-vegetable diet) and to 59 g (low-fat, high-vegetable diet). The saturated fat intake decreased from 28 g to 20 g and to 19 g, and the amount of polyunsaturated fat intake increased from 11 g to 13 g and to 19 g (baseline; low-fat, low-vegetable; low-fat, high-vegetable; respectively). The amount of oxidized LDL in plasma was determined as the content of oxidized phospholipid per ApoB-100 using a monoclonal antibody EO6 (OxLDL-EO6). The median plasma OxLDL-EO6 increased by 27% (P<0.01) in response to the low-fat, low-vegetable diet and 19% (P<0.01) in response to the low-fat, high-vegetable diet. Also, the Lp(a) concentration was increased by 7% (P<0.01) and 9% (P=0.01), respectively. CONCLUSIONS: Alterations in the dietary fat intake resulted in increased plasma concentrations of lipoprotein(a) and OxLDL-EO6.

Plasma homocysteine concentration is decreased by dietary intervention.

High plasma total homocysteine (tHcy) concentration is reported to be a risk factor for vascular diseases. We investigated the extent to which serum folate and plasma tHcy respond to a high intake of natural folate from food. Thirty-seven healthy females volunteered t o participate in a crossover dietary intervention. The study included a baseline period and two 5-week diet periods (low- and high-folate diets) with a 3-week washout in between. The low-folate diet contained one serving of both vegetables and fruit/d, while during the high-folate diet the subjects ate at least seven servings of vegetables, berries, and citrus fruit/d. Serum and erythrocyte (RBC) folate, serum vitamin B (12), and plasma tHcy concentrations were measured at the base-line and at the end of each diet period. The mean concentrations of serum and RBC folate were 11.0 (SD 3.0) nmol/l and 412 (SD 120) nmol/l at the end of the low-folate diet and 78 (95 % CI 62, 94) % and 14 (95 % CI 8, 20) % higher in response to the high-folate diet (P< 0.001). The serum concentration of vitamin B12 remained unchanged during the intervention. The mean plasma tHcy concentration was 8.0 pmol/ at the end of the low-folate diet and decreased by 13 (95% CI 9, 18) % in response to the high-folate diet (P<0.001). In conclusion, a diet high in fresh berries, citrus fruit, and vegetables effectively increases serum and RBC folate and decreases plasma homocysteine.

Dietary modifications and gene polymorphisms alter serum paraoxonase activity in healthy women.

Paraoxonase-1 (PON1), a HDL-associated enzyme, may protect against the development of atherosclerosis. Serum PON1 activity and PON1-mediated capacity of HDL to prevent lipoprotein oxidation are modulated by two common polymorphisms at positions 192 (Gln-->Arg) and 55 (Leu-->Met) of the PON1 gene. We studied the effect of dietary modifications on PON1 activity and the role of PON1 gene polymorphisms in the response. A controlled, crossover dietary intervention of two 5-wk periods was conducted in 37 healthy, nonsmoking women. The two study diets were either low or high in vegetables, and thus in natural antioxidants, with some differences in fatty acid contents. The mean plasma total (-8%, P < 0.001), LDL (-7%, P < 0.01) and HDL (-7%, P < 0.001%) cholesterol, and apolipoprotein A-I (-8%, P < 0.001) concentrations were lower after the high vegetable diet period than after the low vegetable diet period. Also, the serum PON1 activity was lower (P < 0.05) after the high vegetable compared with the low vegetable diet period. The reduction of PON1 activity correlated with the reduction in HDL cholesterol (r = 0.35, P < 0.05). High baseline PON1 activity was related to the presence of the PON1(192Arg) allele (P < 0.001) and PON1(55Leu/Leu) genotype (P < 0.001). The reduction of PON1 activity due to the high vegetable diet was greatest among the women with the PON1(192Arg) allele (P < 0.05) and PON1(55Leu/Leu) genotype (P < 0.05). In conclusion, a diet high in vegetables, berries and fruit reduces PON1 activity, and the response is modulated by the genetic variance of PON1.