Achlorhydria
 | This articleneeds additional citations forverification.(February 2013) |
| Achlorhydria | |
|---|---|
| Other names | Hypochlorhydria |
 | |
| Hydrogen chloride(major component ofgastric acid) | |
| Pronunciation | |
| Specialty | Internal medicine |
| Symptoms | Most of the time none, but may cause and not limited to,heartburn,stomach pain, and early satiety |
| Complications | Anemia,small intestinal bacterial overgrowth |
| Causes | Pernicious anemia,helicobacter pyloriinfection, hypothyroidism, stomach surgery, nutritional deficiencies, and long term use of medications to treat heartburn |
Achlorhydriaandhypochlorhydriarefer to states where the production ofhydrochloric acidin gastric secretions of thestomachand other digestive organs is absent or low, respectively.[1]It is associated with various other medical problems.
Signs and symptoms
[edit]Irrespective of the cause, achlorhydria can result as known complications ofbacterial overgrowthandintestinal metaplasiaand symptoms are often consistent with those diseases:
- gastroesophageal reflux disease[2]
- abdominal discomfort
- early satiety
- weight loss
- diarrhea
- constipation
- abdominal bloating
- anemia
- stomach infection
- malabsorption of food
- carcinomaof stomach
Since acidic pH facilitates the absorption of iron, achlorhydric patients often developiron deficiency anemia.The acidic environment of stomach helps conversion of pepsinogen into pepsin, which is highly important in digesting the protein into smaller components, such as a complex protein into simple peptides and amino acids inside the stomach, which are later absorbed by the gastrointestinal tract.
Bacterial overgrowth andB12 deficiency(pernicious anemia) can cause micronutrient deficiencies that result in various clinical neurological manifestations, including visual changes,paresthesias,ataxia,limb weakness, gait disturbance, memory defects, hallucinations and personality and mood changes.
Risk of particular infections, such asVibrio vulnificus(commonly from seafood) is increased. Even without bacterial overgrowth, low stomach acid (high pH) can lead to nutritional deficiencies throughdecreased absorptionof basic electrolytes (magnesium,zinc,etc.) and vitamins (includingvitamin C,vitamin K,and theB complexof vitamins). Such deficiencies may be involved in the development of a wide range of pathologies, from fairly benign neuromuscular issues to life-threatening diseases.
Causes
[edit]- The slowing of the body's basal metabolic rate associated withhypothyroidism.
- Pernicious anemiawhere there isantibodyproduction againstparietal cellswhich normally produce gastric acid.[3]
- The use ofantacidsor drugs that decrease gastric acid production (such asH2-receptor antagonists) or transport (such asproton pump inhibitors).
- A symptom ofrare diseasessuch asmucolipidosis(type IV).
- A symptom ofHelicobacter pyloriinfection which neutralizes and decreases secretion ofgastric acidto aid its survival in the stomach.[4]
- A symptom ofatrophic gastritisor ofstomach cancer.
- Radiation therapyinvolving the stomach.
- Gastric bypassprocedures such as aduodenal switchand RNY, where the largest acid producing parts of the stomach are either removed or blinded.
- VIPomas(vasoactive intestinal peptides) andsomatostatinomasare both islet cell tumors of the pancreas.
- Pellagra,caused by niacin deficiency.
- Chloride, sodium, potassium, zinc and/or iodine deficiency, as these elements are needed to produce adequate levels ofstomach acid(HCl).
- Sjögren's syndrome,anautoimmune disorderthat destroys many of the body's moisture-producing enzymes.
- Ménétrier's disease,characterized by hyperplasia of mucous cells in the stomach also causing excess protein loss, leading to hypoalbuminemia (presents with abdominal pain and edema).
Risk Factors
[edit]Prevalence
Achlorhydria is present in about 2.5% of the population under 60 years old and about 5% of the population over 60 years old.[5]The incidence increases to around 12% in populations over 80 years old. An absence ofhydrochloric acidincreases with advancing age. A lack of hydrochloric acid produced by the stomach is one of the most common age-related causes of a harmed digestive system.[6]
Among men and women, 27% experience a varying degree of achlorhydria. US researchers found that over 30% of women and men over the age of 60 have little to no acid secretion in the stomach. Additionally, 40% of postmenopausal women have shown to have no basalgastric acidsecretion in the stomach, with 39.8% occurring in females 80 to 89 years old.[6]
Comorbidities
Autoimmune disordersare also linked to advancing age, specificallyautoimmune gastritis,which is when the body produces unwelcomed antibodies and causes inflammation of the stomach.[5]Autoimmune disorders are also a cause for small bacterial growth in the bowel and a deficiency of Vitamin B-12. These have also proved to be factors of acid secretion in the stomach.[7]Autoimmune conditions can often be managed with various treatments; however, little is known about how or if these treatments effect achlorhydria.[5]
Thyroid hormones can contribute to changes in the level of hydrochloric acid in the stomach.Hypothyroidismis associated with a greater risk of developing achlorhydria.[5]
Long term usage of medications or drugs
Extended use of anti-acids, antibiotics, and other drugs can contribute to hypochlorhydria.Proton pump inhibitors(PPIs) are very commonly used to temporarily relieve symptoms conditions such as gastroesophageal reflux andpeptic ulcers.[7]Risk increases as these drugs are taken over a longer time period, often many years, typically beyond the recommended therapeutic usage.
Stress can also be linked to symptoms associated with achlorhydria including constant belching, constipation, and abdominal pain.[7]
Diagnosis
[edit]For practical purposes, gastric pH andendoscopyshould be done in someone with suspected achlorhydria. Older testing methods using fluid aspiration through a nasogastric tube can be done, but these procedures can cause significant discomfort and are less efficient ways to obtain a diagnosis.
A complete 24-hour profile of gastric acid secretion is best obtained during anesophageal pH monitoringstudy.
Achlorhydria may also be documented by measurements of extremely low levels ofpepsinogen A(PgA) (< 17 µg/L) in blood serum. The diagnosis may be supported by high serumgastrinlevels (> 500–1000 pg/mL).[8]
The "Heidelberg test"is an alternative way to measure stomach acid and diagnose hypochlorhydria/achlorhydria.
A check can exclude deficiencies in iron, calcium,prothrombin time,vitamin B-12,vitamin D,andthiamine.Complete blood countwith indices and peripheral smears can be examined to excludeanemia.Elevation ofserumfolateis suggestive of small bowel bacterial overgrowth. Bacterial folate can be absorbed into the circulation.
Once achlorhydria is confirmed, ahydrogen breath testcan check for bacterial overgrowth.
Treatment
[edit]Treatment focuses on addressing the underlying cause of symptoms.
Treatment of gastritis that leads topernicious anemiaconsists of parenteral vitamin B-12 injection. Associated immune-mediated conditions (e.g., insulin-dependentdiabetesmellitus,autoimmune thyroiditis) should also be treated. However, treatment of these disorders has no known effect in the treatment of achlorhydria.
Achlorhydria associated withHelicobacter pyloriinfection may respond toH. pylorieradication therapy, although resumption of gastric acid secretion may only be partial and it may not always reverse the condition completely.[9]
Antimicrobial agents, including metronidazole, amoxicillin/clavulanate potassium, ciprofloxacin, andrifaximin,can be used to treat bacterial overgrowth.
Achlorhydria resulting from long-termproton-pump inhibitor(PPI) use may be treated by dose reduction or withdrawal of the PPI.
Prognosis
[edit]Little is known on the prognosis of achlorhydria, although there have been reports of an increased risk of gastric cancer.[10]
A 2007 review article noted that non-Helicobacterbacterial species can be cultured from achlorhydric (pH > 4.0) stomachs, whereas normal stomach pH only permits the growth ofHelicobacterspecies. Bacterial overgrowth may cause false-positiveH. pyloritest results due to the change in pH fromureaseactivity.[11]
Small bowel bacterial overgrowth is a chronic condition. Retreatment may be necessary once every 1–6 months.[12]Prudent use of antibacterials now calls for anantimicrobial stewardshippolicy to manageantibiotic resistance.[13]
See also
[edit]References
[edit]- ^Kohli, Divyanshoo R., Jennifer Lee, and Timothy R. Koch. "Achlorhydria." Medscape. Ed. B S. Anand. N.p., 29 Apr. 2015. Web. 25 May 2015.
- ^Kines, Kasia, and Tina Krupczak. "Nutritional Interventions for Gastroesophageal Reflux, Irritable Bowel Syndrome, and Hypochlorhydria: A Case Report." Integr Med. 2016 Aug 15; 15(4): 49-53.
- ^"Achlorhydria".Medscape.Jul 15, 2016.Retrieved11 October2018.
- ^El-Omar EM, Oien K, El-Nujumi A, et al. (1997). "Helicobacter pylori infection and chronic gastric acid hyposecretion".Gastroenterology.113(1): 15–24.doi:10.1016/S0016-5085(97)70075-1.PMID9207257.
- ^abcdTeam 2, Health Jade (2019-09-02)."Achlorhydria definition, causes, symptoms, diagnosis, treatment & prognosis".Health Jade.Retrieved2019-11-15.
{{cite web}}:CS1 maint: numeric names: authors list (link) - ^abEnglish, James (2018-11-25)."Gastric Balance: Heartburn Not Always Caused by Excess Acid".Nutrition Review.Retrieved2019-11-15.
- ^abcKines, Kasia; Krupczak, Tina (August 2016)."Nutritional Interventions for Gastroesophageal Reflux, Irritable Bowel Syndrome, and Hypochlorhydria: A Case Report".Integrative Medicine: A Clinician's Journal.15(4): 49–53.ISSN1546-993X.PMC4991651.PMID27574495.
- ^Divyanshoo Rai Kohli."Achlorhydria Workup".Medscape.Retrieved13 September2014.
- ^Iijima, K.; Sekine, H.; Koike, T.; Imatani, A.; Ohara, S.; Shimosegawa, T. (2004)."Long-term effect of Helicobacter pylori eradication on the reversibility of acid secretion in profound hypochlorhydria".Alimentary Pharmacology and Therapeutics.19(11): 1181–1188.doi:10.1111/j.1365-2036.2004.01948.x.PMID15153171.
- ^Svendsen JH, Dahl C, Svendsen LB, Christiansen PM (1986). "Gastric cancer risk in achlorhydric patients. A long-term follow-up study".Scand. J. Gastroenterol.21(1): 16–20.doi:10.3109/00365528609034615.PMID3952447.
- ^Brandi G (Aug 2006). "Urease-positive bacteria other than Helicobacter pylori in human gastric juice and mucosa".Am J Gastroenterol.101(8): 1756–61.doi:10.1111/j.1572-0241.2006.00698.x.PMID16780553.S2CID205786158.
- ^Divyanshoo Rai Kohli."Achlorhydria Follow-up".Medscape.Retrieved13 September2014.
- ^Lee CR, Cho IH, Jeong BC, Lee SH (Sep 12, 2013)."Strategies to minimize antibiotic resistance".Int J Environ Res Public Health.10(9): 4274–305.doi:10.3390/ijerph10094274.PMC3799537.PMID24036486.