2.6. Clinical Metabolic Parameters and Measures of Choline Status
Clinical metabolic profiles were determined in fasting serum. Fasting serum glucose and lipids, including total cholesterol, HDL-cholesterol (HDL-C), and triglycerides, were measured by spectrophotometry by Quest Diagnostics (Seacaucus, NJ, USA). LDL-cholesterol (LDL-C) was determined using the Martin–Hopkins calculation. Serum electrolytes (sodium, potassium, chloride, calcium), carbon dioxide, measures of protein status, liver, and kidney function (blood urea nitrogen, serum total protein, albumin, globulin, albumin:globulin ratio, bilirubin, alkaline phosphatase), and the acute-phase liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were additionally measured by Quest Diagnostics. High-sensitivity C-reactive protein (hsCRP) was measured enzymatically utilizing a Cobas c-111 clinical analyzer (Roche Diagnostics, Florham Park, NJ, USA). Serum concentrations of ketones (total ketone bodies, beta-hydroxybutyrate, acetoacetate, and acetone), choline, betaine, and TMAO were measured by LabCorp (Morrisville, NC, USA).