Researchers, writing in the journal Heart, pooled data from 23 studies and found that social isolation or feelings of loneliness were tied to an increased risk for coronary heart disease (冠心病 ) and strokes.The studies included data from 181,006 men and women ages 18 and over. There were 4,628 coronary events and 3,002 strokes in follow-up periods __26___from three to 21 years. Three of the papers__27__loneliness, 18 looked at social isolation and two included both. Social isolation and loneliness were determined with questionnaires; the researchers depended on medical records and death__28__for determining coronary events and strokes.The scientists found that loneliness and social isolation increased the __29__risk of having a heart attack or a death from heart disease by 29 percent, and the risk of stroke by 32 percent. There were no__30__between men and women."People have tended to focus from a policy point of view on__31__ lonely people to make them more__32__," said the lead author, Nicole K. Valtorta, a research fellow at the University of York in England. "Our study__33__that if this is a risk factor, then we should be trying to prevent the risk factor in the first place."The authors__34__that this was a review of observational studies and did not__35__cause and effect.A. acknowledgeB. certificatesC. connectedD. demonstratesE. differencesF. establishG. formatsH、measuredI、narrowJ、permanentK、producesL、rangingM、relativeN、submittingO、targeting