Bioenergetics Basics

This test measures glucose concentration in peritoneal dialysate fluid, the solution used during peritoneal dialysis for kidney failure. Glucose naturally diffuses from the dialysate into the bloodstream during treatment, and measuring residual glucose helps assess dialysate dwell time and treatment effectiveness. Changes in dialysate glucose levels can indicate peritoneal membrane changes or absorption problems affecting dialysis adequacy and treatment outcomes.

Carbon dioxide (CO2) in blood, measured as bicarbonate, is crucial for acid-base balance and respiration. This test assesses how well your lungs remove CO2 and how well your kidneys regulate acid balance. Elevated CO2 suggests respiratory problems or metabolic alkalosis, while low CO2 may indicate hyperventilation or metabolic acidosis. Results help diagnose breathing disorders, kidney disease, and serious metabolic imbalances affecting multiple organ systems.

Calcium is an essential mineral critical for bone health, muscle function, nerve signaling, and blood clotting. This test measures calcium levels in serum or plasma, reflecting overall calcium balance in the body. About 99% of calcium is stored in bones, while the remaining 1% circulates in the blood and is tightly regulated. Abnormal serum calcium may indicate parathyroid disorders, vitamin D deficiency, kidney disease, or certain malignancies. Both hypocalcemia (low calcium) and hypercalcemia (high calcium) can cause serious symptoms including muscle cramps, cardiac arrhythmias, and neurological changes.

Homocysteine is an amino acid produced during protein metabolism. Elevated blood homocysteine, called hyperhomocysteinemia, is an independent risk factor for cardiovascular disease, stroke, and blood clots. High levels may indicate deficiencies in vitamins B12, B6, or folate, kidney disease, or genetic factors affecting homocysteine metabolism. This test helps identify cardiovascular risk and vitamin deficiencies. Lowering homocysteine through B-vitamin supplementation or dietary changes may reduce heart disease and stroke risk.

Dehydroepiandrosterone sulfate (DHEA-S) is an androgen hormone produced by the adrenal glands. A 24-hour urine test measures total DHEA-S excretion, reflecting adrenal hormone production. DHEA-S levels naturally decline with age and can indicate adrenal insufficiency or dysfunction if abnormally low, or adrenal tumors or excess androgen production if abnormally high. This test helps evaluate adrenal gland function, hormonal imbalances, and conditions affecting hormone metabolism.

Insulin is a hormone produced by the pancreas that regulates blood glucose levels by allowing cells to absorb sugar for energy. An insulin test measures circulating insulin levels, which rise after eating or during fasting depending on metabolic function. Elevated fasting insulin may indicate insulin resistance, where cells don't respond properly to insulin, increasing risk for prediabetes and metabolic syndrome. Low insulin levels may suggest pancreatic dysfunction or diabetes.

Prolactin is a hormone produced by the pituitary gland that stimulates milk production in nursing mothers but should remain low in non-pregnant individuals. Elevated prolactin levels (hyperprolactinemia) can cause irregular menstruation, infertility, erectile dysfunction, and inappropriate milk production. High prolactin may indicate a pituitary tumor, certain medications, or thyroid disorders. This test is essential for evaluating fertility issues, sexual dysfunction, and menstrual irregularities.

This test measures total 25-hydroxyvitamin D, combining both vitamin D2 (from foods and supplements) and vitamin D3 (from sun exposure and food). The 25-hydroxy form is the best indicator of overall vitamin D status because it reflects total body stores. This single measurement efficiently assesses vitamin D adequacy for bone health, immune function, and calcium regulation without measuring multiple vitamin D forms.