Differences and similarities in the etiology and the incidence of cirrhosis in the Nordic countries

Development of severe alcohol related liver disease over four decades in Iceland: impact of increased access and use of alcohol

OBJECTIVE

Limited data exist on the association between per capita alcohol consumption and incidence of alcohol related liver disease (ARLD). The aims were to analyse this relationship and assess prevalence of ARLD in Iceland and among patients treated for alcohol use disorder (AUD) and its impact on outcomes.

METHODS

A retrospective study on all patients diagnosed with severe ARLD: alcohol related cirrhosis (ARC) and alcohol related hepatitis (ARH) in Iceland 1984-2020. Medical records were scrutinized for clinical features, severity of ARLD, proportion undergoing treatment for AUD, data on abstinence and long-term outcomes.

RESULTS

A total of 314 patients, males 76%, median age 56 years, fulfilled the predetermined criteria for ARLD. Median MELD was 17, 73% with Child-Pugh B/C and 70/314 (22%) who had ARH. Incidence of ARLD increased from 0.77 cases per 100 000 inhabitants annually 1984-2000 to 6.1 per 100 000 in 2016-2020. Per capita alcohol consumption increased from 4.3 Liters to 7.5 L in in the same time periods. Overall 220/314 (70%) with ARLD had undergone treatment for AUD. Of all individuals who had AUD treatment during the study period (n = 21.845), 1% were diagnosed with ARLD. Patients who underwent treatment for AUD after the ARLD diagnosis had better prognosis than those who had treatment prior to ARLD diagnosis (hazard ratio 2.5 [95% CI 1.3-5.0]).

CONCLUSIONS

The incidence of ARLD increased 8-fold during the study period coinciding with 74% increase in per capita alcohol consumption. Patients with prior diagnosis of AUD had worse prognosis that needs special attention.

A nationwide population-based prospective study of cirrhosis in Iceland

Background & Aims

The incidence of cirrhosis in Iceland has been the lowest in the world with only 3 cases per 100,000 inhabitants. Alcohol consumption has almost doubled in Iceland from 1980 to 2016. Obesity has also risen and hepatitis C virus has spread among people who inject drugs in Iceland. The aim of this study was to evaluate the effects of these risk factors on the incidence and aetiology of cirrhosis in Iceland.

Methods

The study included all patients diagnosed with cirrhosis for the first time during 2010–2015. Diagnosis was based on liver histology or 2 of 4 criteria: cirrhosis on imaging, ascites, varices, and/or elevated INR.

Results

Overall, 157 patients were diagnosed, 105 (67%) males, mean age 61 years. The overall incidence was 9.7 cases per 100,000 inhabitants annually. Alcohol was the only underlying cause in 48/157 (31%), non-alcoholic fatty liver disease (NAFLD) in 34/157(22%), and alcohol and hepatitis C together in 23/157(15%) were the most common causes. Only 6% of patients had an unknown cause of cirrhosis. Upon diagnosis, the median model for end-stage liver disease score was 11 (IQR 8–15), 53% were of Child-Pugh class A whereas 61 (39%) had ascites, 11% encephalopathy, and 8% variceal bleeding. In all, 25% of deaths were from HCC and 25% from liver failure.

Conclusion

A major increase in incidence of cirrhosis has occurred in Iceland associated with increases in alcohol consumption, obesity, and hepatitis C. In a high proportion NAFLD was the aetiology and very few had unknown cause of cirrhosis. The highest death rate was from HCC.

Lay summary

In a nationwide population-based study from Iceland, including all patients diagnosed with cirrhosis of the liver over a period of 5 years, we found the incidence of new cases had increased 3-fold compared with a previous study 20 years ago. The increase is attributable to increased alcohol consumption, an epidemic of diabetes and obesity, and infection with the hepatitis C virus. Furthermore, we found that with thorough investigations, a specific cause for cirrhosis could be found in 94% of patients. Patients with cirrhosis frequently die of liver cancer and other complications related to their liver disease.

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The incidence of cirrhosis in Iceland has been the lowest among western countries.

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In this nationwide prospective study, all patients diagnosed with cirrhosis of the liver in Iceland over a period of 5 years were included.

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The incidence of cirrhosis had increased 3-fold compared with a study 10 years earlier owing to increased alcohol consumption, obesity, and hepatitis C.

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With thorough investigations a specific cause for cirrhosis could be found in 94% of patients.

Complications of cirrhosis. A 50 years flashback

In patients with cirrhosis and portal hypertension, it is largely the frequency and severity of complications relating to the diseased liver, degree of portal hypertension and hemodynamic derangement that determine the prognosis. It can be considered as a multiple organ failure that apart from the liver involves the heart, lungs, kidneys, the immune systems and other organ systems. Progressive fibrosis of the liver and subsequent metabolic impairment leads to a systemic and splanchnic arteriolar vasodilatation. With the progression of the disease development of portal hypertension leads to formation of esophageal varices and ascites. The circulation becomes hyperdynamic with cardiac, pulmonary as well as renal consequences for dysfunction and reduced survival. Infections and a changed cardiac function known as cirrhotic cardiomyopathy may be involved in further aggravation of other complications such as renal failure precipitating the hepatorenal syndrome. Patients with end-stage liver disease and related complications as for example the hepatopulmonary syndrome can only radically be treated by liver transplantation.

Scandinavian epidemiological research in gastroenterology and hepatology

In the last decades, a large number of epidemiological studies in gastroenterology and hepatology have originated from the Scandinavian countries. With the help of large health databases, with good validity and other registries related to patient outcomes, researchers from the Scandinavian countries have been able to make some very important contributions to the field. These countries, Sweden, Norway, Finland, Denmark and Iceland, have all universal access to health care and have shown to be ideal for epidemiological research. Population-based studies have been frequent and follow-up studies have been able to describe the temporal trends and changes in phenotypes. Our ability in Scandinavia to follow up defined groups of patients over time has been crucial to learn the natural history of many gastrointestinal and liver diseases and often in a population-based setting. Patient-related outcomes measures will probably gain increasing importance in the future, but Scandinavian gastroenterologists and surgeons are likely to have a better infrastructure for such endeavors compared to most other populations. Thus, there is a bright future for international competitive research within the field of gastrointestinal and liver diseases in Scandinavia.