GERD Increases Risk for Nontuberculous Mycobacterial Pulmonary Disease

Patients with gastroesophageal reflux disease (GERD) are at increased risk for nontuberculous mycobacterial pulmonary disease (NTM-PD), according to study findings published in CHEST.

Nontuberculous mycobacterial pulmonary disease often co-occurs with GERD, frequently increasing the number and severity of symptoms. Researchers attribute this association to gastric-to-pulmonary micro-aspiration of gastric acid, which continuously destroys the protective barrier and lining of the airways. This gradual pulmonary deterioration predisposes patients with GERD to pulmonary infection.

Researchers in South Korea conducted a national cohort study using data obtained between 2002 and 2015 from the Korean National Health Insurance Service-National Sample Cohort. The researchers assessed whether GERD is associated with an increased risk for NTM-PD. They compared the incidence and risk for NTM-PD between 17,424 patients with and 69,696 patients (controls) without GERD. The 2 patient groups were matched on the basis of age, sex, type of health insurance, and Charlson comorbidity index (CCI) score. Risk factors for NTM-PD were also evaluated among patients in the GERD group. Gray testing was used to calculate the cumulative incidence for NTM-PD between the patient groups.

Among all patients included in the analysis, 90% were aged 40 years and older, and 50.1% were men; the most common comorbidities included diabetes (28.3%), asthma (14.7%), cerebrovascular disease (12.1%), and chronic obstructive pulmonary disease (8.2%).

Researchers found that patients in the GERD group had a significantly increased risk for NTM-PD compared with those in the control group (subdistribution hazard ratio [HR], 3.36; 95% CI, 2.10-5.37).

The age- and sex-adjusted incidence of NTM-PD was assessed during a median follow-up period of 5.1 (IQR, 3.0-7.2) years. The incidence of NTM-PD was 34.8 per 100,000 patient-years (py) among patients in the GERD group compared with 10.5 per 100,000 py among those in the control group (P <.001).

To determine risk factors associated with developing NTM-PD, multivariable Cox regression was performed and adjusted on the basis of age, sex, health insurance type, pulmonary and extrapulmonary comorbidities, and CCI score. In patients with GERD, those who were aged 60 years and older age (adjusted HR, 3.57; 95% CI, 1.58-8.07) and those with bronchiectasis (adjusted HR, 18.69; 95% CI, 6.68-52.28) were at increased risk for NTM-PD.

Further analysis of patients with GERD showed that those who developed NTM-PD demonstrated an increased incidence of all-cause mortality (13,321 vs 5932 per 100,000 py; P =.049) and disease-related hospitalizations or emergency department visits (5403 vs 801 per 100,000 py; P =.011) vs those who did not develop the disease.

These findings may not be generalizable to other patient populations. Other limitations include the ability to evaluate data on smoking history, BMI, pulmonary function test results, and types of NTM-PD.

Researchers also noted that “Developing NTM-PD in patients with GERD is associated with increased healthcare use.”