Objective To explore the clinical characteristics and risk factors of occult pneumonia in advanced elderly patients.Methods A total of 170 advanced elderly patients with community-acquired pulmonary infection in geriatric department of Xijing hospital from January 2014 to October 2017 were enrolled.Patients were divided into two groups:the observation group (with occult pneumonia,n=80)and the control group(without occult pneumonia,n =90).Clinical data of patients were collected,and clinical characteristics and related risk factors of occult pneumonia in elderly patients were analyzed.Results There was no statistically significant difference in the positive rate of sputum culture and the distribution of pathogenic bacteria between the two groups (P ＞ 0.05).Gram-negative bacteria predominated in pathogenic bacteria.The hospitalization time was longer in the observation group than in the control group[(17.3 ± 3.0) d vs.(10.3 ± 3.9) d,P ＜ 0.05].The mortality rate was higher in the observation group than in the control group(10.0 ％ vs.3.3 ％,P ＜ 0.05).The age was older in the observation group than in the control group[(87.0± 1.7) years vs.(82.0± 2.4) years,P ＜ 0.05].The incidences of diabetes,Alzheimer's disease,hypothyroidism and long-term bed rest were higher in the observation group than in the control group (P ＜ 0.05).Multivariate logistic regression analysis showed that age (OR =6.93),dementia (OR =4.32),hypothyroidism(OR =4.89) were independent risk factors for occult pneumonia (P ＜ 0.05).Conclusions The pathogenic bacteria in advanced elderly patients with occult pneumonia are mainly gram-negative bacteria.The positive rate of CT scan confirmed-occult pneumonia is much higher than that by chest X-ray.The advanced elderly patients with occult pneumonia have longer hospitalization time and higher mortality rates.Old age,senile dementia and hypothyroidism are independent risk factors for occult pneumonia in advanced elderly patients.

AMP-activated protein kinase (AMPK), known as a sensor and a master of cellular energy balance, integrates various regulatory signals including anabolic and catabolic metabolic processes. Accompanying the application of genetic methods and a plethora of AMPK agonists, rapid progress has identified AMPK as an attractive therapeutic target for several human diseases, such as cancer, type 2 diabetes, atherosclerosis, myocardial ischemia/reperfusion injury and neurodegenerative disease. The role of AMPK in metabolic and energetic modulation both at the intracellular and whole body levels has been reviewed elsewhere. In the present review, we summarize and update the paradoxical role of AMPK implicated in the diseases mentioned above and put forward the challenge encountered. Thus it will be expected to provide important clues for exploring rational methods of intervention in human diseases.