Non-Alcoholic Fatty Liver Disease (NAFLD/MASLD): Causes, Stages, Treatment & Care in Shanghai

What Is Non-Alcoholic Fatty Liver Disease?

Non-alcoholic fatty liver disease (NAFLD, 非酒精性脂肪性肝病) is the most common chronic liver condition worldwide, affecting an estimated 25–30% of the global adult population and up to 29–32% of adults in China. It is defined as the accumulation of excess fat (triglycerides) in liver cells (肝细胞脂肪变性) in the absence of significant alcohol consumption, viral hepatitis, or other specific causes of liver disease.

In 2023, the international hepatology community adopted a new nomenclature: MASLD (Metabolic dysfunction-Associated Steatotic Liver Disease), reflecting the central role of metabolic dysfunction in its pathogenesis. The older term NAFLD remains widely used in clinical practice and patient communication.

NAFLD is not a single disease but a spectrum of conditions ranging from simple fat accumulation (steatosis) to progressive inflammatory liver disease (steatohepatitis), fibrosis, cirrhosis, and ultimately liver failure or hepatocellular carcinoma.

The NAFLD Disease Spectrum

Stage 1: Simple Steatosis (单纯性脂肪肝)

• Fat accumulation in ≥5% of liver cells without significant inflammation or fibrosis
• Generally benign; most patients do not progress to advanced disease
• Fully reversible with lifestyle modification
• Usually asymptomatic; discovered incidentally on ultrasound or blood tests

Stage 2: Non-Alcoholic Steatohepatitis (NASH / MASH)

• Fat accumulation plus liver cell inflammation and injury (hepatocyte ballooning, lobular inflammation)
• Affects approximately 20–30% of NAFLD patients
• Carries significant risk of progression to fibrosis and cirrhosis
• May cause fatigue, right upper quadrant discomfort, elevated liver enzymes (ALT, AST)
• Diagnosis requires liver biopsy for definitive confirmation

Stage 3: Fibrosis (肝纤维化)

• Scar tissue replaces normal liver architecture; graded F1–F4
• F1–F2: Mild to moderate fibrosis; liver function generally preserved
• F3: Advanced fibrosis; significant risk of progression to cirrhosis
• F4: Cirrhosis — irreversible structural damage; portal hypertension may develop

Stage 4: Cirrhosis and End-Stage Liver Disease

• Decompensated cirrhosis: ascites, variceal bleeding, hepatic encephalopathy, jaundice
• NAFLD-related cirrhosis is now the leading indication for liver transplantation in many countries
• Annual risk of hepatocellular carcinoma (HCC): 1–2% in NAFLD cirrhosis; HCC can also occur in advanced fibrosis without cirrhosis

Who Is at Risk? Risk Factors and Associations

NAFLD is strongly linked to metabolic syndrome and its components:

• Obesity: Present in 51–82% of NAFLD patients; visceral (abdominal) fat is more strongly associated than total body fat; NAFLD can occur in lean individuals (“lean NAFLD” — particularly common in East Asians)
• Type 2 diabetes: 50–75% of T2DM patients have NAFLD; diabetes dramatically accelerates fibrosis progression
• Insulin resistance: The central driver of hepatic fat accumulation; present even in lean NAFLD
• Dyslipidemia: High triglycerides, low HDL cholesterol
• Hypertension: Independent risk factor for NAFLD progression
• Metabolic syndrome: Having 3 or more metabolic syndrome criteria increases NAFLD risk 4–6 fold
• Genetic factors: PNPLA3 I148M variant (common in East Asians) significantly increases NAFLD risk and severity; TM6SF2, MBOAT7 variants also implicated
• Gut microbiome dysbiosis: Emerging evidence links altered gut bacteria to hepatic fat accumulation and inflammation
• Sleep apnea: Intermittent hypoxia promotes hepatic inflammation and fibrosis
• Hypothyroidism: Associated with NAFLD through metabolic effects
• Polycystic ovary syndrome (PCOS): High NAFLD prevalence in women with PCOS

Symptoms: Why NAFLD Is Often Missed

NAFLD is frequently called a “silent disease” because most patients have no symptoms until advanced fibrosis or cirrhosis develops:

• Simple steatosis and early NASH: usually completely asymptomatic
• Some patients report fatigue, mild right upper quadrant discomfort, or a sense of fullness
• Elevated liver enzymes (ALT, AST) on routine blood tests are often the first clue — but up to 50% of NAFLD patients have normal liver enzymes
• Advanced fibrosis/cirrhosis: fatigue, muscle wasting, spider angiomas, palmar erythema, splenomegaly, ascites

Diagnosis

Blood Tests

• Liver function tests (LFTs): ALT and AST may be elevated (typically 1–4x upper limit of normal in NASH); GGT often elevated; normal LFTs do not exclude NAFLD
• Fasting lipid panel: Hypertriglyceridemia, low HDL common
• Fasting glucose and HbA1c: Screen for diabetes and insulin resistance
• Fasting insulin / HOMA-IR: Quantifies insulin resistance
• Thyroid function (TSH): Exclude hypothyroidism
• Exclude other liver diseases: Hepatitis B and C serology, autoimmune liver panel (ANA, ASMA, AMA), iron studies (hemochromatosis), ceruloplasmin (Wilson's disease)
• Non-invasive fibrosis scores: FIB-4 index (age × AST / [platelets × √ALT]) and NAFLD Fibrosis Score (NFS) stratify fibrosis risk without biopsy

Imaging

• Liver ultrasound: First-line; detects steatosis when ≥20–30% of hepatocytes are affected; cannot reliably detect fibrosis or distinguish steatosis from NASH
• FibroScan (transient elastography): Non-invasive measurement of liver stiffness (fibrosis) and controlled attenuation parameter (CAP, steatosis); widely available in Shanghai; preferred non-invasive fibrosis assessment tool
• MRI-PDFF (proton density fat fraction): Most accurate non-invasive quantification of liver fat; used in clinical trials and complex cases
• MR elastography: Highly accurate non-invasive fibrosis assessment; available at major centers
• CT scan: Can detect steatosis but involves radiation; not preferred for routine NAFLD assessment

Liver Biopsy

• Still the gold standard for definitive NASH diagnosis and fibrosis staging
• Indicated when non-invasive tests are inconclusive, when other liver diseases need to be excluded, or before initiating specific therapies
• Risks: pain, bleeding (1%), rare serious complications; performed under ultrasound guidance
• The NAS (NAFLD Activity Score) grades steatosis, inflammation, and ballooning; fibrosis staged F0–F4

Treatment

Lifestyle Modification: The Foundation of Treatment

For all stages of NAFLD, lifestyle modification is the most effective and evidence-based intervention:

• Weight loss: The single most powerful intervention
  • 5–10% body weight loss: reduces liver fat and inflammation
  • ≥10% body weight loss: improves or resolves NASH in most patients; reduces fibrosis
  • ≥12% body weight loss: associated with fibrosis regression even in advanced disease
• Dietary modification:
  • Mediterranean diet: strongest evidence base; emphasizes vegetables, legumes, whole grains, fish, olive oil; reduces liver fat and cardiovascular risk
  • Reduce refined carbohydrates and added sugars (particularly fructose from soft drinks and processed foods — fructose is directly lipogenic in the liver)
  • Avoid alcohol entirely — even moderate alcohol accelerates NAFLD progression
  • Limit red and processed meat; increase fiber intake
  • Coffee consumption (3–4 cups/day) is associated with reduced liver fibrosis and HCC risk — one of the few dietary factors with consistent hepatoprotective evidence
• Physical activity: Both aerobic exercise and resistance training reduce liver fat independently of weight loss; target ≥150 minutes of moderate-intensity exercise per week; even 30 minutes of brisk walking daily produces measurable benefit
• Treat metabolic comorbidities: Optimize blood sugar, blood pressure, and lipids — each independently affects NAFLD progression

Pharmacological Treatment

As of 2024–2025, resmetirom (Rezdiffra) — a thyroid hormone receptor-β agonist — became the first FDA-approved drug specifically for NASH with moderate-to-advanced fibrosis (F2–F3). It is not yet widely available in China but represents a landmark in NAFLD pharmacotherapy.

Other agents with evidence or current use:

• GLP-1 receptor agonists (semaglutide, liraglutide): Significant reduction in liver fat and NASH resolution; semaglutide 2.4 mg showed 59% NASH resolution in Phase 2 trial; Phase 3 ESSENCE trial results awaited; also reduces cardiovascular risk
• GLP-1/GIP dual agonist (tirzepatide): Impressive liver fat reduction in SURMOUNT trials; Phase 3 SYNERGY-NASH trial ongoing
• Pioglitazone (thiazolidinedione): Improves NASH histology; recommended by AASLD guidelines for NASH with fibrosis in T2DM patients; causes weight gain and fluid retention
• Vitamin E (800 IU/day): Improves NASH histology in non-diabetic patients; not recommended long-term due to possible increased all-cause mortality at high doses
• SGLT-2 inhibitors (empagliflozin, dapagliflozin): Reduce liver fat and enzymes; cardiovascular and renal benefits; increasingly used in NAFLD with T2DM
• Statins: Safe in NAFLD (contrary to historical concern); reduce cardiovascular risk; modest hepatic benefit; should not be withheld due to NAFLD

Bariatric Surgery

• Most effective intervention for NAFLD in severely obese patients (BMI ≥35, or ≥32.5 in Asians with metabolic comorbidities)
• Produces sustained weight loss of 25–35%; resolves NASH in 85–90% and improves fibrosis in 70–80%
• Sleeve gastrectomy and Roux-en-Y gastric bypass are most commonly performed
• Requires multidisciplinary evaluation; not appropriate for decompensated cirrhosis

Liver Transplantation

• For end-stage NAFLD cirrhosis with decompensation or HCC meeting transplant criteria
• NAFLD recurs in the transplanted liver if metabolic risk factors are not addressed post-transplant

Monitoring: How Often Should You Be Checked?

Where to Seek Specialist Care in Shanghai

Renji Hospital (仁济医院), Shanghai Jiao Tong University — Gastroenterology & Liver Disease

Renji Hospital's Gastroenterology Department is one of Shanghai's leading centers for liver disease, with dedicated expertise in NAFLD, viral hepatitis, and advanced liver fibrosis management:

• Gastroenterology at Renji Hospital Shanghai — Department overview and how to access specialist liver care
• Dr. Chen Shiyao (陈世耀) — Director of Gastroenterology at Renji Hospital; expert in liver disease and gastrointestinal conditions
• Dr. Shen Xizhong (沈锡中) — Expert in Gastroenterology and Liver Disease at Renji Hospital; specialist in chronic liver conditions including NAFLD and hepatitis

Longhua Hospital (龙华医院) — Integrative Endocrinology & Metabolic Management

For patients seeking integrative management of the metabolic drivers of NAFLD — including TCM-based dietary therapy, herbal medicine, and lifestyle medicine combined with conventional endocrinology:

• Integrative Endocrinology & Diabetes at Longhua Hospital Shanghai — TCM-integrated metabolic management including obesity, insulin resistance, and fatty liver programs

How CMCS Can Help

NAFLD management requires coordinated care across gastroenterology, endocrinology, nutrition, and lifestyle medicine. CMCS connects international patients with Shanghai's leading liver specialists, providing:

• Priority appointments with hepatologists and gastroenterologists at Renji Hospital and other leading centers
• Pre-consultation review of liver function tests, imaging reports, and FibroScan results
• Medical interpretation during all consultations and biopsy procedures
• Coordination of comprehensive metabolic evaluation (diabetes, lipids, thyroid, sleep apnea)
• Guidance on accessing newly approved NAFLD therapies in Shanghai
• Long-term follow-up coordination including HCC surveillance programs

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