Statistical & Clinical Analysis
Geriatric Nutritional Risk Index (GNRI) Formula: Bouillanne Albumin & Lorentz Ideal Weight
Calculate Olivier Bouillanne et al.’s (2005) Geriatric Nutritional Risk Index GNRI = 1.489 * Albumin_gL + 41.7 * MIN(1, Weight / Lorentz_Ideal_Weight) and classify Major (< 82), Moderate (82 to < 92), Low (92 to <= 98), and Normal (> 98) nutrition-related mortality risk.
Why Bouillanne’s GNRI replaces forgotten "usual body weight" with Lorentz Ideal Weight—and caps Weight/WLo <= 1!
Elderly hospitalized patients rarely know their pre-illness "usual body weight," rendering the classic Buzby Nutritional Risk Index unusable in geriatric wards! Olivier Bouillanne et al. (2005, American Journal of Clinical Nutrition) solved this by substituting Lorentz Ideal Body Weight W_Lo (for men: Height_cm - 100 - (Height_cm - 150) / 4; for women: Height_cm - 100 - (Height_cm - 150) / 2.5) into GNRI = 1.489 * Albumin_g/L + 41.7 * MIN(1, Current_Weight_kg / W_Lo)!
Notice two critical clinical rules in Bouillanne’s specification: (1) Serum albumin MUST be entered in g/L (multiply g/dL by 10: e.g., 3.2 g/dL = 32 g/L!), and (2) When Current_Weight > W_Lo, the weight ratio is CAPPED at 1.0 via MIN(1, W / W_Lo) so sarcopenic obesity never masks hypoalbuminemic malnutrition! GNRI stratifies nutrition-related morbidity/mortality risk into 4 validated tiers: < 82 Major Risk, 82 to < 92 Moderate Risk, 92 to <= 98 Low Risk, and > 98 No Nutritional Risk!
| GNRI Score Range | Bouillanne et al. (2005) Nutrition-Related Risk Tier | Hospital / Dialysis / Heart-Failure Prognosis |
|---|---|---|
| GNRI < 82 | Major Nutrition-Related Risk | Highest infectious & 6-month mortality risk — intensive nutrition support |
| 82 <= GNRI < 92 | Moderate Nutrition-Related Risk | Elevated complication risk — targeted protein/energy supplementation |
| 92 <= GNRI <= 98 | Low Nutrition-Related Risk | Mild risk — monitor intake & serial albumin |
| GNRI > 98 | Normal / No Nutrition-Related Risk | Standard inpatient diet |
Bouillanne (2005) Geriatric Nutritional Risk Index GNRI (with Sex-Specific Lorentz W_Lo & Ratio <= 1 Cap)
Computes Lorentz Ideal Weight from Height_cm (B3) and Sex (B2: "M" or "F"), caps W / W_Lo at 1.0, and adds 1.489 * Albumin_g/L (B5).
=IF(OR(AND(UPPER(TRIM(B2 & "")) <> "M", UPPER(TRIM(B2 & "")) <> "F"), B3 < 120, B4 <= 0, B5 <= 0), "Invalid GNRI Inputs (Use Sex M/F, Height cm >= 120, Albumin in g/L)", ROUND(1.489 * B5 + 41.7 * MIN(1, B4 / (B3 - 100 - (B3 - 150) / IF(UPPER(TRIM(B2 & "")) = "M", 4, 2.5))), 2))4-Tier GNRI Nutrition-Related Risk Classifier (< 82 Major / 82–<92 Moderate / 92–98 Low / > 98 No Risk)
Classifies GNRI into Bouillanne et al.’s four prognostic tiers.
=IF(OR(AND(UPPER(TRIM(B2 & "")) <> "M", UPPER(TRIM(B2 & "")) <> "F"), B3 < 120, B4 <= 0, B5 <= 0), "Invalid GNRI Inputs", IF(1.489 * B5 + 41.7 * MIN(1, B4 / (B3 - 100 - (B3 - 150) / IF(UPPER(TRIM(B2 & "")) = "M", 4, 2.5))) < 82, "Major Nutritional Risk (GNRI < 82)", IF(1.489 * B5 + 41.7 * MIN(1, B4 / (B3 - 100 - (B3 - 150) / IF(UPPER(TRIM(B2 & "")) = "M", 4, 2.5))) < 92, "Moderate Nutritional Risk (82 to < 92)", IF(1.489 * B5 + 41.7 * MIN(1, B4 / (B3 - 100 - (B3 - 150) / IF(UPPER(TRIM(B2 & "")) = "M", 4, 2.5))) <= 98, "Low Nutritional Risk (92 to 98)", "No Nutritional Risk (GNRI > 98)"))))Try the example
Use the original values or change them to test your understanding.