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Lipids · LIVE

Sampson estimated LDL-C

Sampson LDL-C

Estimate LDL-C from total cholesterol, HDL, and triglycerides using Sampson 2020.

LIVE $0.005 USDC GET /api/calc/sampson

Markdown: /docs/sampson.md · Canonical: https://magentlab.com/docs/sampson

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Estimate LDL-C from total cholesterol, HDL, and triglycerides using Sampson 2020.

When to use

When an agent needs Sampson LDL arithmetic (including triglycerides up to 800 mg/dL) and must not apply Friedewald TG/5.

When not to use

  • Not a diagnosis and not a statin order. Direct LDL assay is out of scope.
  • Triglycerides above 800 mg/dL (or 9.03 mmol/L) are rejected. Sampson 2020 is not applied above that cap.
  • Sampson 2020 only. Not Friedewald 1972 and not Martin/Hopkins.

Formula

LDL-C = TC/0.948 - HDL/0.971 - (TG/8.56 + TG*(TC-HDL)/2140 - TG^2/16100) - 9.44 (mg/dL)

Citation

Title
A new equation for calculation of low-density lipoprotein cholesterol in patients with normolipidemia and/or hypertriglyceridemia
Authors
Sampson M, Ling C, Sun Q, et al.
Source
JAMA Cardiol. 2020;5(5):540-548
DOI
10.1001/jamacardiol.2020.0013

Worked example

TC 200, HDL 50, TG 150 mg/dL

Given: hdl_mg_dl=50total_cholesterol_mg_dl=200triglycerides_mg_dl=150

  1. nonHDL = 200 - 50 = 150
  2. TG term = 150/8.56 + 150*150/2140 - 150^2/16100
  3. LDL-C = 200/0.948 - 50/0.971 - TG term - 9.44 = 123.4 mg/dL

Also searched as

  • Sampson equation
  • Sampson LDL-C
  • NIH LDL equation
  • calculated LDL 800
  • Sampson 2020
  • LDL-C hypertriglyceridemia

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/sampson?total_cholesterol_mg_dl=200&hdl_mg_dl=50&triglycerides_mg_dl=150

Full URL: https://api.magentlab.com/api/calc/sampson?total_cholesterol_mg_dl=200&hdl_mg_dl=50&triglycerides_mg_dl=150

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/sampson?total_cholesterol_mg_dl=200&hdl_mg_dl=50&triglycerides_mg_dl=150"

Parameters

Name Type Required Description
total_cholesterol_mg_dl number optional Total cholesterol in mg/dL (50-500). Provide the full mg/dL set or the full mmol/L set, not mixed.
hdl_mg_dl number optional HDL cholesterol in mg/dL (5-150). Same unit system as the other lipids.
triglycerides_mg_dl number optional Triglycerides in mg/dL (10-800). Values above 800 are rejected; Sampson 2020 is not applied above 800 mg/dL.
total_cholesterol_mmol_l number optional Total cholesterol in mmol/L (1.3-12.9). Converted as mg/dL = mmol/L * 38.67. Do not mix with mg/dL keys.
hdl_mmol_l number optional HDL cholesterol in mmol/L (0.1-3.9). Converted as mg/dL = mmol/L * 38.67.
triglycerides_mmol_l number optional Triglycerides in mmol/L (0.1-9.03). Cap is the SI stand-in for 800 mg/dL (mg/dL = mmol/L * 88.57). The Sampson equation is applied in mg/dL.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/sampson Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

  • 1 to 25 items. Each item uses the same keys as the GET query parameters.
  • POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
  • The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
  • HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
  • Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
  • x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "hdl_mg_dl": "50",
      "total_cholesterol_mg_dl": "200",
      "triglycerides_mg_dl": "150"
    },
    {
      "hdl_mg_dl": "50",
      "total_cholesterol_mg_dl": "200",
      "triglycerides_mg_dl": "150"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/sampson",
  "items": [
    {
      "unit": "mg_dl",
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Sampson M, Ling C, Sun Q, et al.",
        "doi": "10.1001/jamacardiol.2020.0013",
        "id": "sampson-2020",
        "source": "JAMA Cardiol. 2020;5(5):540-548",
        "title": "A new equation for calculation of low-density lipoprotein cholesterol in patients with normolipidemia and/or hypertriglyceridemia"
      },
      "formula": "sampson",
      "formula_expression": "LDL-C = TC/0.948 - HDL/0.971 - (TG/8.56 + TG*(TC-HDL)/2140 - TG^2/16100) - 9.44 (mg/dL)",
      "hdl_mg_dl": 50.0,
      "ldl_c_mg_dl": 123.4,
      "ldl_c_mmol_l": 3.2,
      "total_cholesterol_mg_dl": 200.0,
      "triglycerides_mg_dl": 150.0
    },
    {
      "unit": "mg_dl",
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Sampson M, Ling C, Sun Q, et al.",
        "doi": "10.1001/jamacardiol.2020.0013",
        "id": "sampson-2020",
        "source": "JAMA Cardiol. 2020;5(5):540-548",
        "title": "A new equation for calculation of low-density lipoprotein cholesterol in patients with normolipidemia and/or hypertriglyceridemia"
      },
      "formula": "sampson",
      "formula_expression": "LDL-C = TC/0.948 - HDL/0.971 - (TG/8.56 + TG*(TC-HDL)/2140 - TG^2/16100) - 9.44 (mg/dL)",
      "hdl_mg_dl": 50.0,
      "ldl_c_mg_dl": 123.4,
      "ldl_c_mmol_l": 3.2,
      "total_cholesterol_mg_dl": 200.0,
      "triglycerides_mg_dl": 150.0
    }
  ]
}

Response

Field Type Description
formula string sampson
formula_expression string Exact Sampson 2020 expression
unit string mg_dl or mmol_l, the unit system supplied
total_cholesterol_mg_dl number Total cholesterol in mg/dL (converted when SI inputs are used)
hdl_mg_dl number HDL cholesterol in mg/dL (converted when SI inputs are used)
triglycerides_mg_dl number Triglycerides in mg/dL (converted when SI inputs are used)
ldl_c_mg_dl number Estimated LDL-C in mg/dL, 1 decimal
ldl_c_mmol_l number Estimated LDL-C in mmol/L, 1 decimal
citation object Sampson JAMA Cardiol 2020 citation
disclaimer string Not-a-device notice

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "unit": "mg_dl",
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Sampson M, Ling C, Sun Q, et al.",
    "doi": "10.1001/jamacardiol.2020.0013",
    "id": "sampson-2020",
    "source": "JAMA Cardiol. 2020;5(5):540-548",
    "title": "A new equation for calculation of low-density lipoprotein cholesterol in patients with normolipidemia and/or hypertriglyceridemia"
  },
  "formula": "sampson",
  "formula_expression": "LDL-C = TC/0.948 - HDL/0.971 - (TG/8.56 + TG*(TC-HDL)/2140 - TG^2/16100) - 9.44 (mg/dL)",
  "hdl_mg_dl": 50.0,
  "ldl_c_mg_dl": 123.4,
  "ldl_c_mmol_l": 3.2,
  "total_cholesterol_mg_dl": 200.0,
  "triglycerides_mg_dl": 150.0
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP Code When
400 invalid_cholesterol provide all of total_cholesterol_mg_dl (50-500), hdl_mg_dl (5-150), and triglycerides_mg_dl, or all of total_cholesterol_mmol_l (1.3-12.9), hdl_mmol_l (0.1-3.9), and triglycerides_mmol_l, not mixed. Returned before settlement; you are not charged.
400 invalid_sampson_triglyceride triglycerides_mg_dl must be 10-800; triglycerides_mmol_l must be 0.1-9.03. Sampson is not applied above 800 mg/dL. Returned before settlement; you are not charged.
400 invalid_lipid_inputs computed LDL-C would be negative; check total cholesterol, HDL, and triglycerides. Returned before settlement; you are not charged.
400 invalid_items POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400 invalid_item_count items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400 invalid_item each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

  • Friedewald LDL-C — Estimate LDL-C from total cholesterol, HDL, and triglycerides using Friedewald 1972.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

  • HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged.
  • exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
  • HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
  • Execution is timeout-bounded and concurrency-capped.
  • Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.