Cobalamin Intake and Related Biomarkers: Examining Associations With Mortality Risk Among Adults With Type 2 Diabetes in NHANES

Abstract

Supplementary materials MMA measurementMMA was measured in venous plasma and/or serum by gas chromatography-mass spectrophotometry (GC/MS) in NHANES 1999-2004 and measured by liquid chromatography-mass spectrophotometry (LC-MS/MS) in NHANES 2011-2014 after butanol derivatization. According to the in-house comparison for the measurement of MMA (n = 326), The LC-MS/MS assay showed excellent correlation (r = 0.99) and agreement (Deming regression, Bland-Altman analysis) compared to the prior GC/MS method. MMA concentrations in pairs of serum and plasma were comparable. The protocols have been described before (

The Regulation and Characterization of Mitochondrial-Derived Methylmalonic Acid in Mitochondrial Dysfunction and Oxidative Stress: From Basic Research to Clinical Practice

“…Studies have demonstrated that elevated MMA levels in diabetes patients showed more severe peripheral neuropathy [ 60 , 61 ]. Similarly, our recent prospective cohort study in type 2 diabetes patients also found that MMA accumulation was positively associated with increased mortality risk [ 62 ]. Obesity and diabetes may play a critical biological role in the metabolic process of MMA in the setting of diseases.…”

Association of Serum Homocysteine with Cardiovascular and All-Cause Mortality in Adults with Diabetes: A Prospective Cohort Study

“…Self-reported cardiovascular disease consisted of coronary heart disease, myocardial infarction, heart failure, and stroke. Duration of diabetes and diabetic peripheral complications (diabetic ulcer/sore, meroparesthesia, or retinopathy) were extracted from diabetic questionnaires [ 22 ]. Prescribed medications were recorded during the preceding 30 days.…”

“…Body mass index (BMI) was calculated as weight (in kilograms) divided by height (in meters) squared. Hypertension was defined by antihypertensive treatment, the average systolic blood pressure ≥ 140 mmHg or the diastolic blood pressure ≥ 90 mmHg at baseline [ 22 ]. Blood and urine samples were collected, processed, and transported to central laboratories following validated procedures.…”

“…Urine albumin and creatinine levels were tested with a fluorescent immunoassay and Jaffe rate reaction, respectively. Urine albumin excretion was calculated as urine albumin divided by urine creatinine which was presented as the urine albumin-creatinine ratio (UACR, mg/g) [ 22 ].…”

Identifying Distinct Risk Thresholds of Glycated Hemoglobin and Systolic Blood Pressure for Rapid Albuminuria Progression in Type 2 Diabetes From NHANES (1999–2018)

“…Diabetes was defined if each condition was satisfied in the following items according to the recent American Diabetes Association (ADA) recommendation ( 19 ): (1) Previous diagnosis of type 2 diabetes by doctors (2) Fasting blood glucose levels greater than or equal to 7.0 mmol/L (126 mg/dL) (3) Postprandial 2 h plasma glucose levels greater than or equal to 11.1 mmol/L (200 mg/dL) after a standard 75-g oral glucose tolerance test (4) HbA1c levels were 6.5% (48 mmol/mol) or higher (5) The use of insulin or hypoglycemic drugs. Possible type 1 diabetes patients were defined as those aged <20 years who were only treated with insulin ( 20 ).…”