RESUMEN
A systematic review and meta-analysis was conducted to assess the relationship between the common dietary antioxidants vitamin C, vitamin E, and ß-carotene and type 2 diabetes (T2D) and related traits. MEDLINE, Embase, and the Cochrane Library were searched for relevant publications up until May 2023. Studies were eligible if they had a cohort, case-control, or randomized controlled trial (RCT) design and examined dietary intake, supplementation, or circulating levels of these antioxidants as exposure, and insulin resistance, ß-cell function, or T2D incidence as outcomes. Summary relative risks (RR) or mean differences (MD) with 95% confidence intervals (CI) were estimated using random-effects models. The certainty of the evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluations framework. Among 6190 screened records, 25 prospective observational studies and 15 RCTs were eligible. Inverse associations were found between dietary and circulating antioxidants and T2D (observational studies). The lowest risk was seen at intakes of 70 mg/d of vitamin C (RR: 0.76; CI: 0.61, 0.95), 12 mg/d of vitamin E (RR: 0.72; CI: 0.61, 0.86), and 4 mg/d of ß-carotene (RR: 0.78; CI: 0.65, 0.94). Supplementation with vitamin E (RR: 1.01; CI: 0.93, 1.10) or ß-carotene (RR: 0.98; CI: 0.90, 1.07) did not have a protective effect on T2D (RCTs), and data on vitamin C supplementation was limited. Regarding insulin resistance, higher dietary vitamin C (RR: 0.85; CI: 0.74, 0.98) and vitamin E supplementation (MD: -0.35; CI: -0.65, -0.06) were associated with a reduced risk. The certainty of evidence was high for the associations between T2D and dietary vitamin E and ß-carotene, and low to moderate for other associations. In conclusion, moderate intakes of vitamins C, E, and ß-carotene may lower risk of T2D by reducing insulin resistance. Lack of protection with supplementation in RCTs suggests that adequate rather than high intakes may play a role in T2D prevention. This systematic review and meta-analysis was registered in PROSPERO with registration number CRD42022343482.
Asunto(s)
Antioxidantes , Ácido Ascórbico , Diabetes Mellitus Tipo 2 , Suplementos Dietéticos , Vitamina E , beta Caroteno , Diabetes Mellitus Tipo 2/prevención & control , Diabetes Mellitus Tipo 2/sangre , Humanos , beta Caroteno/administración & dosificación , beta Caroteno/farmacología , beta Caroteno/sangre , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/farmacología , Vitamina E/administración & dosificación , Vitamina E/farmacología , Antioxidantes/administración & dosificación , Resistencia a la Insulina , Dieta , Factores de Riesgo , Masculino , Femenino , Persona de Mediana Edad , Adulto , AncianoRESUMEN
OBJECTIVE: To investigate the impact of a reminder (i.e., a mailed letter or short telephone call) from the pharmacy to patients, compared with no reminder in a control group, on the pick-up rates of unclaimed e-prescriptions. METHOD: Patients, with e-prescriptions transmitted to four large community pharmacies in two counties in northern Sweden and remaining unclaimed after 4 weekdays, were randomised to one of two intervention groups (a mailed reminder or a short telephonic reminder) or a control group. MAIN OUTCOME MEASURES: Rates of patients' pick-up of their e-prescriptions at follow-up after about 1, 2 and 3 weeks. RESULTS: Altogether, 320 patients with e-prescriptions, transmitted from March 21 through April 6 and not picked-up or dispensed, were identified and randomised to the study. There were no statistically significant differences in overall pick-up rates between the groups or with respect to gender. However, pick-up rates increased with increasing age. Higher pick-up rates were observed for two subgroups (but only in the mailed reminder group compared with controls)--for cardiovascular drugs to men and for respiratory drugs to adolescents and young adults. CONCLUSION: A reminder (i.e., a mailed letter or short telephone call) from the pharmacy to the patient had no statistically significant effect on overall pick-up rates of unclaimed e-prescriptions compared with no reminders.