# Martin 2013 LDL-C Calculator (magent)

> Martin 2013 LDL-C Calculator (magent) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Estimates LDL cholesterol using the Martin 2013 method with an adjustable TG:VLDL-C factor from a 180-cell lookup table, given total cholesterol, HDL, and triglycerides in mg/dL.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/martin_ldl
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/martin-2013-ldl-c-calculator-magent-a4c5cc38
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_X_Y7ZR2qHdgELaCfKq635

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability martin-2013-ldl-c-calculator-magent-a4c5cc38
```

Example prompt: Can you calculate the LDL cholesterol using the Martin 2013 method for a patient with a total cholesterol of 210 mg/dL, HDL of 55 mg/dL, and triglycerides of 150 mg/dL?

## When to prefer this

Use this endpoint when you need LDL-C estimation via the Martin 2013 method specifically — particularly when triglycerides are elevated enough to make the Friedewald factor-of-5 less accurate, but still below 400 mg/dL. Prefer this over Friedewald when you want stratum-adjusted TG:VLDL-C factors from the published 180-cell table. Do not use for triglycerides >= 400 mg/dL (use Sampson or direct LDL measurement instead), and do not use for mmol/L inputs.

## Known failure modes

- Triglycerides >= 400 mg/dL are rejected — the Martin 2013 paper excludes this range
- HDL >= total cholesterol causes rejection because non-HDL-C would be zero or negative
- Values outside stated ranges (TC 50-500, HDL 5-150, TG 7-399) return validation errors
- Missing any of the three required query parameters returns an error
- mmol/L inputs are not converted and will produce incorrect results if submitted as mg/dL

## How this service works

Martin 2013 estimated LDL-C from total cholesterol, HDL, and triglycerides in mg/dL. Adjustable TG:VLDL-C factor from the published 180-cell table by non-HDL-C and TG strata. Not Friedewald factor 5, not Sampson, not a diagnosis or statin order.

## Output

Returns an estimated LDL-C value in mg/dL computed via the Martin 2013 method, using the appropriate TG:VLDL-C conversion factor from the 180-cell table indexed by non-HDL-C and triglyceride strata. Does not return a diagnosis or treatment recommendation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "total_cholesterol_mg_dl",
      "hdl_mg_dl",
      "triglycerides_mg_dl"
     ],
     "properties": {
      "hdl_mg_dl": {
       "type": "number",
       "description": "HDL cholesterol in mg/dL (5-150). Must be less than total cholesterol so non-HDL-C is positive."
      },
      "triglycerides_mg_dl": {
       "type": "number",
       "description": "Triglycerides in mg/dL (7-399). The Martin 2013 table first TG row starts at 7. Values of 400 or higher are rejected; that is the paper's primary analysis cut."
      },
      "total_cholesterol_mg_dl": {
       "type": "number",
       "description": "Total cholesterol in mg/dL (50-500). mg/dL only; magent does not convert mmol/L."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/martin-2013-ldl-c-calculator-magent-a4c5cc38/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)