Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet

Background: Studies of the efficacy of vitamin C treatment for fatigue have yielded inconsistent results. One of the reasons for this inconsistency could be the difference in delivery routes. Therefore, we planned a clinical trial with intravenous vitamin C administration. Methods: We evaluated the effect of intravenous vitamin C on fatigue in office workers. A group of 141 healthy volunteers, aged 20 to 49 years participated in this randomized, double-blind, controlled clinical trial. The trial group received 10 grams of vitamin C with normal saline intravenously, while the placebo group received normal saline only. Since vitamin C is a well-known antioxidant, oxidative stress was measured. Fatigue score, oxidative stress, and plasma vitamin C levels were measured before intervention, and again two hours and one day after intervention. Adverse events were monitored. Results: The fatigue scores measured at two hours after intervention and one day after intervention were significantly different between the two groups (p = 0.004); fatigue scores decreased in the vitamin C group after two hours and remained lower for one day. Trial also led to higher plasma vitamin C levels and lower oxidative stress compared to the placebo group (p < 0.001, p < 0.001, respectively). When data analysis was refined by dividing each group into high-baseline and low-baseline subgroups, it was observed that fatigue was reduced in the lower baseline vitamin C level group after two hours and after one day (p = 0.004). The same did not hold for the higher baseline group (p = 0.206). Conclusion: Thus, intravenous vitamin C reduced fatigue at two hours, and the effect persisted for one day. There were no significant differences in adverse events between two groups. High dose intravenous vitamin C proved to be safe and effective against fatigue in this study. Trial Registration: The clinical trial registration of this trial is http://ClinicalTrials.gov NCT00633581.

Improvement of dietary habits is recommended for the management of cerebrovascular and cardiovascular diseases (CCVD). This study aimed to evaluate the dietary habits of CCVD patients and compare them with the general population by using the Diet Quality Index—International (DQI-I). Data from the Korean National Health and Nutrition Examination Surveys (2013–2016) were used. Cardiovascular diseases included myocardial infarction, angina pectoris, and heart failure; and cerebrovascular diseases included stroke, cerebral infarction, and hemorrhage. In total, 12,683 subjects over 20 years old were included, comprising 718 CCVD patients and 11,965 non-CCVD subjects. Survey-weighted multiple linear regression analyses with adjustment for covariates were used to compare DQI-I scores. The mean total DQI-I scores for the CCVD and non-CCVD groups were 66.7 ± 9.2 and 67.8 ± 9.2, respectively. After adjusting for covariates, the CCVD group had DQI-I scores significantly lower than the non-CCVD group (coefficient −1.13, p-value = 0.011). In the analysis of each DQI-I component, the CCVD group had lower scores for variety (coefficient −0.54, p-value = 0.004) and adequacy (coefficient −0.86, p-value = 0.001). In this study, using nationally representative data, dietary habits of CCVD patients were shown to be lower in quality than non-CCVD subjects. Therefore, evaluation and education of adequate dietary habits are needed in the management of CCVD patients.

Background: This study aimed to explore the relationship between fruit intake, changes in fruit intake, and changes in cardiometabolic factors in people with obesity. Methods: A total of 21,270 subjects (8,718 men, 12,552 women) aged 40 years and over, from the Korean-based Genome and Epidemiology Study, were followed up for an average of 4.4 years. Fruit intake was assessed using a food frequency questionnaire at baseline and the second follow-up. The beta coefficient and confidence intervals for changes in cardiometabolic risk factors according to fruit consumption were calculated using a linear regression model. Results: In men, the abdominal circumference decreased with changes in fruit intake (P=0.029). Fruit intake and increased fruit intake in men were associated with a lower systolic blood pressure (P=0.012 and P=0.02, respectively) and lower triglyceride levels (P=0.002 and P<0.001, respectively). In women, abdominal circumference decreased with both fruit intake and increased fruit intake (P<0.001 and P=0.013, respectively). Systolic blood pressure and triglycerides tended to decrease only with fruit intake (P=0.048 and P<0.001, respectively). Unlike in men, fasting blood glucose tended to decrease in women with both fruit intake and increased fruit intake (P=0.011 and P=0.005, respectively). Conclusion: Fruit intake and increased fruit intake may have beneficial effects on cardiometabolic risk factors among individuals who are obese.

Kim S, et al. J Korean Med Sci. 2016 Feb;31(2):159-163. https://doi.org/10.3346/jkms.2016.31.2.159