Gout & Hyperuricemia

痛风 + 高尿酸

Place · Level 3 · Condition

尿酸代谢 · 嘌呤 + 果糖 + 酒精 · 含糖饮料肝脏一刀 (KHK) · 完整水果 vs 液体果糖 · 樱桃、咖啡、低脂奶保护 · ULT 药物

Connected to · 5

regulates · 4

Fructose Metabolism
KHK pathway: liquid fructose (HFCS / soft drinks) depletes hepatic ATP within 1-2 min → AMP → IMP → uric acid. Choi 2008 BMJ (N=46,393 men): ≥2 soft drinks/d raised gout risk 85%. Whole fruit / honey at slower absorption rates does NOT trigger equivalent risk.
Alcohol Metabolism
Dual mechanism: (1) ADH/ALDH lactate output competes with urate for renal OAT excretion → serum urate ↑; (2) beer adds purine load (guanosine). Choi 2004 Lancet (N=47,150): beer ≥2/d × 2.5 gout risk, spirits 1.6×, wine neutral.
Joints · Cartilage & Tendon
A joint that turns suddenly red, hot and swollen is not the wear-and-tear story: urate crystals dropping into the joint space ignite acute inflammation. This is the branch to rule out first in joint pain.
Kidney Stones
Uric-acid stones make up 10-15% of kidney stones; gout patients have 10-30× elevated risk. Low urine pH + high uric acid are shared mechanisms. Allopurinol/febuxostat treat both gout and prevent uric-acid stones + some CaOx stones (urate-seeding theory).

contrast · 1

Hyperuricemia
A red flag on a lab report is not gout: hyperuricaemia is almost entirely asymptomatic and most people never have an attack. Reading it as gout-imminent — strict elimination, repeated clinic visits — is the commonest overreaction.

Urate + flare

Stop 1/5

尿酸代谢 + 痛风发作

The plain version first: gout = too much uric acid in the blood — enough that it crystallizes into needle-like shards inside a joint, which jab like ground glass: red, swollen, searing. Below: where uric acid comes from, why it overflows, and how the crystals settle.

Gout = hyperuricemia + monosodium urate crystal deposition in joint cavities → severe pain + inflammation.

Epidemiology:

·China ~ 120 million hyperuricemic + 15 million gout patients (Chinese Diabetes Society 2022)
Rapid shift to younger ages: mostly 50+ in the 1980s, now widespread at 30-40 in the 2020sMale:female ≈ 4-7:1 (premenopausal estrogen protection)Seafood + beer + red-meat culture is the core driver
Urate metabolism:

End product of purine metabolism (nucleic-acid breakdown + dietary purine)70% endogenous (cell apoptosis + DNA turnover) + 30% dietaryExcretion: 2/3 renal + 1/3 intestinal (uricase is inactive in humans, unlike dogs / pigs)Serum urate (SUA) upper limit: men ≤ 7 mg/dL (420 µmol/L) / women ≤ 6 mg/dL (360 µmol/L)Flare risk: at SUA > 9 mg/dL, annual attack rate 5-10%
Crystal deposition:

In plasma, SUA saturates at > 6.8 mg/dL and may crystallise beyond thatCrystals prefer cool + distal sites: the great toe (first MTP joint) is the first presentation in 50%+Acute flare: extreme pain within 24 hours + redness/swelling + tenderness, lasts 3-10 daysLong-term recurrence → tophi: subcutaneous nodules, elbow / pinna / fingersChronic destructive arthritis + urate nephropathy (stones + chronic renal injury)
Link to metabolic syndrome:

Hyperuricemia ↔ MetSyn ↔ T2D ↔ NAFLD ↔ CVD are mutually reinforcing risksFructose metabolism → AMP → urate (covered in atlas fructose-metabolism L4)Hyperuricemia as an independent CV risk factor (partial consensus, partial controversy)
Diagnosis:

Clinical: monoarticular acute inflammation + high SUA + typical intercritical patternGold standard: joint aspiration + needle-shaped urate crystals under polarised lightImaging: dual-energy CT + high-resolution ultrasound can visualise crystals
Differentials:

Pseudogout (CPPD): calcium pyrophosphate deposition, older patients + knee / wristSeptic arthritis: redness/swelling + fever + systemic symptoms, must aspirate to excludeRheumatoid arthritis: symmetric polyarticular + morning stiffness + RF + anti-CCP

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Educational content, not medical advice — consult a clinician.

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