Plasma Magnesium Concentrations and Risk of Incident Cancer in Adults with Hypertension: A Nested Case-Control Study.

OBJECTIVE: The association between plasma magnesium and risk of incident cancer remains inconclusive in previous studies. We aimed to investigate the prospective relationship of baseline plasma magnesium concentrations with the risk of incident cancer and to examine possible effect modifiers. METHODS: A nested case-control study with 228 incident cancer cases and 228 matched controls was conducted using data from the China Stroke Primary Prevention Trial (CSPPT), a randomized, double-blind, controlled trial, conducted from May 2008 to August 2013. Study outcomes included incident cancer and its subtypes. RESULTS: When plasma magnesium concentrations were assessed as quartiles, a significantly higher incident risk of total cancer was found in participants in quartile 1 (<0.76 mmol/L; odds ratio [OR] = 2.70; 95% CI: 1.33-5.49) and quartile 4 (≥0.89 mmol/L; OR = 2.05; 95% CI: 1.12-3.76), compared with those in quartile 3 (0.83 to <0.89 mmol/L). In cancer site-specific analyses, similar trends were found for gastrointestinal cancer, esophageal cancer, gastric cancer, breast cancer, lung cancer, and other cancers. Furthermore, none of the variables, including age, sex, current smoking status, current alcohol intake, BMI, systolic blood pressure, and total cholesterol levels at baseline significantly modified the association between plasma magnesium and cancer risk. CONCLUSIONS: Both low and high plasma magnesium concentrations were significantly associated with an increased incident risk of cancer, compared with the reference concentrations of 0.83 to <0.89 mmol/L among hypertensive adults.

Baseline Plasma Zinc and Risk of First Stroke in Hypertensive Patients: A Nested Case-Control Study.

Background and Purpose- We aimed to examine the relation of baseline plasma zinc with the risk of first stroke and investigate any possible effect modifiers in hypertensive patients. Methods- The study population was drawn from the CSPPT (China Stroke Primary Prevention Trial), using a nested case-control design, including 599 first stroke cases and 599 matched controls. Results- Compared with participants with baseline plasma zinc <106.9 µg/dL (median), a significantly lower risk of first hemorrhagic stroke was found in those with plasma zinc ≥106.9 µg/dL (multivariate-adjusted odds ratio, 0.45; 95% CI, 0.21-0.94). Furthermore, the inverse plasma zinc-first hemorrhagic stroke association was significantly stronger in participants with body mass index ≥25.0 kg/m2 or plasma copper <100.1 µg/dL at baseline (Pinteraction <0.05 for both variables). However, there was no significant association between plasma zinc and first ischemic stroke (<103.3 versus ≥103.3 µg/dL [median]; multivariate-adjusted odds ratio, 1.16; 95% CI, 0.83-1.61). Conclusions- In this sample of hypertensive patients, we found a significant, inverse association between plasma zinc and first hemorrhagic stroke. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00794885.