Functional Dyspepsia, 2016

Nicholas J. Talley; Marjorie M. Walker; Gerald Holtmann


Curr Opin Gastroenterol. 2016;32(6):467-473. 

In This Article

Epidemiology and Overlap

A review has concluded that there are important clinical and epidemiological differences between functional dyspepsia in the West and the East.[7] The authors suggest that while functional dyspepsia may be more prevalent in the West, PDS symptoms may be more common in the East, and symptom improvement post Helicobacter pylori eradication may be higher in the East. However, the differences reported were not based on head-to-head studies in most cases and remain somewhat speculative. The different methods applied and linguistic differences may account for much of the variation reported.

The causes of functional dyspepsia remain to be established, but recent epidemiological studies may provide vital new clues. Koloski et al.[8] examined early-life environmental factors in the genesis of functional dyspepsia and IBS. In a study from Sydney, Australia, of 767 patients randomly selected from the community and prospectively followed up, 12% developed new onset functional dyspepsia. The only risk factor identified to be linked to functional dyspepsia was exposure to herbivore pets such as horses. It is interesting to speculate that exposure to intestinal parasites from these pets may be of relevance here in view of the strong and consistent observation that eosinophilia of the duodenum is linked to functional dyspepsia and in particular PDS.[1,2] Bedroom sharing and a shorter duration of breast-feeding were risk factors for IBS but not functional dyspepsia. Paula et al.,[9] in a nested case-control study from Mayo Clinic in the United States, looked at nonenteric infections and antibiotic use in new onset cases with a functional gastrointestinal disorder including functional dyspepsia. There was no significant increase in nonenteric infection rates in incident cases compared with those who did not develop gastrointestinal symptoms. However, treatment with an antibiotic for a nongastrointestinal infection was a significant risk factor, with nearly a two-fold increased risk. These results need confirmation but suggest that the intestinal microbiome and its response to antibiotics may play a role in the pathogenesis of functional gastrointestinal syndromes, including possibly functional dyspepsia.

In patients with GERD, sleep disturbances are prevalent, but less is known about sleep disorders in functional dyspepsia. Vakil et al.[10] studied 193 patients with objectively documented GERD (including by pH monitoring) and 137 with functional dyspepsia who did not have objective evidence of GERD. Reflux symptoms were common in functional dyspepsia, and while sleep disturbances over seven nights were more prevalent in the GERD group related to symptoms of reflux (65%), in functional dyspepsia reflux symptoms impacted on sleep in a substantial minority (46%). This study provides further evidence of gut–brain interactions and emphasizes that GERD and functional dyspepsia can be part of the same spectrum.

An intriguing report links functional dyspepsia to hepatitis C.[11] The authors point out that this chronic viral infection is associated with pain and fatigue, and of 252 cases with chronic hepatitis C, 66% fulfilled Rome III criteria for functional dyspepsia, most often PDS. Those who were obese or with a higher liver fibrosis score were at significantly higher risk, and while those with hepatitis C were older, were more often male, and more often smoked, these factors were not significant. These results must be confirmed, but could chronic viral infections account for some who currently have idiopathic PDS?