Biochemistry Tests: Understanding Blood Sugar, BMP, LFT, and KFT

🧪 Biochemistry Blood Tests Explained: Glucose, BMP, LFT & Kidney Function

1. Introduction

Blood biochemistry tests are indispensable for gauging the health of vital organs and metabolism. Covering blood sugar, electrolytes, liver enzymes, cholesterol, and kidney function, they form the backbone of preventive healthcare, chronic disease management, and treatment monitoring.

2. Blood Sugar: Fasting Glucose & HbA1c

What it measures:

• Fasting glucose shows your blood sugar level after 8–12 hours without eating.

• HbA1c reflects average blood glucose over 2–3 months.

Normal values:

• Fasting glucose: 70–100 mg/dL; 100–125 mg/dL indicates prediabetes; ≥126 mg/dL indicates diabetes (confirmed twice).

• HbA1c: <5.7% normal, 5.7–6.4% prediabetes, ≥6.5% diabetes.

Clinical significance:
Elevated fasting glucose suggests insulin resistance or diabetes risk. HbA1c tracks long-term control and is critical for treatment decisions and monitoring.

3. Basic Metabolic Panel (BMP)

What it includes:
Also called CHEM-7, BMP measures eight markers: glucose, electrolytes (sodium, potassium, chloride, CO₂), calcium, BUN, and creatinine .

Typical ranges:

• Sodium: 136–144 mmol/L

• Potassium: 3.5–5.0 mmol/L

• Chloride: 98–107 mmol/L

• CO₂: 22–30 mmol/L

• BUN: 7–21 mg/dL

• Creatinine: 0.6–1.3 mg/dL

• Calcium: 8.5–10.2 mg/dL source.

Why it matters:
BMP evaluates metabolic status and organ function. High BUN or creatinine suggest kidney issues, while electrolyte imbalances can lead to cardiovascular or neurological problems. Calcium levels hint at bone metabolism or parathyroid function.

4. Liver Function Tests (LFT)

Components:
LFT includes ALT, AST, ALP, bilirubin, albumin, and total protein. These markers reveal liver cell health, bile flow, and protein synthesis capacity .

Reference ranges:

• ALT: 7–56 IU/L

• AST: 0–35 IU/L

• ALP: 41–147 IU/L

• Bilirubin: 0.2–1.9 mg/dL

• Albumin: 3.9–5.0 g/dL source.

Clinical relevance:
Elevated ALT/AST indicates liver inflammation or injury; AST/ALT ratios may suggest specific causes—over 2:1 often points to alcoholic liver disease source. High ALP often signals bile duct obstruction; low albumin may stem from liver impairment or malnutrition.

5. Kidney Function Tests (KFT)

Key markers:
BUN, serum creatinine, and eGFR gauge kidney health. Urine albumin-creatinine ratio (uACR) helps detect early kidney damage source.

Normal ranges:

• BUN: 7–20 mg/dL

• Creatinine: Men 0.7–1.3 mg/dL; Women 0.6–1.1 mg/dL source.

• eGFR: 90–120 mL/min/1.73 m²; <60 suggests chronic kidney disease source.

• Normal uACR: <30 mg/g source.

Clinical significance:
High creatinine/BUN levels or low eGFR indicate decreased kidney filtration. uACR detects early kidney damage, often from diabetes or hypertension. Monitoring guides staging and early interventions.

6. Integrated Diagnostic Insight

Combining these tests builds a multidimensional health profile:

• High fasting glucose + rising creatinine = diabetic nephropathy.

• Elevated ALT/AST with dyslipidemia suggests fatty liver or metabolic syndrome.

• BMP electrolyte disturbances + low eGFR informs safe medication and hydration strategies.

• Lipid profile abnormalities plus kidney dysfunction highlight cardiovascular risk.

This holistic view supports effective preventive strategies and disease management.