Researchers in Iran studied over 10,000 adults to understand why certain health conditions tend to happen together. They found that about 4 out of 10 people had multiple chronic diseases at the same time. By grouping people with similar health patterns, scientists discovered three main groups: those who were healthy, those with cholesterol problems, and those with heart and metabolic issues. Age, gender, exercise, sleep, and lifestyle choices all played a role in who developed these disease clusters. This research helps doctors understand that health problems don’t happen randomly—they often come in predictable patterns that we can work to prevent.

The Quick Take

  • What they studied: How multiple chronic diseases cluster together in adults and what factors make someone more likely to develop these disease combinations
  • Who participated: 10,131 adults living in Fasa, a city in southern Iran, ranging from young adults to elderly participants with varying income levels and employment status
  • Key finding: About 40% of adults had two or more chronic diseases happening at the same time. The researchers found three distinct groups: healthy people (67%), those mainly with cholesterol problems (14%), and those with heart and metabolic diseases (19%). Getting older, being female, not exercising enough, and sleeping less than 8 hours increased the risk of having multiple diseases.
  • What it means for you: If you’re getting older or female, paying attention to exercise, sleep, and cholesterol becomes even more important. These lifestyle changes may help prevent multiple diseases from developing together. However, this study was done in Iran, so results may differ in other countries with different healthcare systems and populations.

The Research Details

This was a cross-sectional study, which means researchers looked at a large group of people at one point in time rather than following them over years. They collected information from 10,131 adults in Iran about their health conditions, lifestyle habits, sleep patterns, exercise, income level, and education. The researchers then used a special statistical method called latent class analysis, which is like sorting people into groups based on which diseases they have—similar to how you might group songs by genre even though each song is unique. This method helps find hidden patterns that might not be obvious when looking at individual diseases one at a time.

Instead of studying one disease at a time, this approach looks at how diseases cluster together. This is important because people rarely have just one health problem—they usually have several that develop together. Understanding these patterns helps doctors predict who is at highest risk and design better prevention programs. The latent class analysis method is particularly valuable because it reveals which disease combinations actually occur in real life, not just which ones could theoretically happen together.

This study has good strengths: it included over 10,000 people, which is a large sample size that makes results more reliable. The study was well-designed and published in a respected scientific journal. However, because it only looked at people at one moment in time, we can’t prove that the risk factors actually cause the diseases—only that they’re connected. The study was done in Iran, so the results may not apply exactly the same way to other countries with different populations and healthcare systems.

What the Results Show

The research identified three distinct groups of people based on their disease patterns. The largest group (about 67%) had no chronic diseases or very few. The second group (14%) mainly had high cholesterol and related lipid problems. The third group (19%) had the most serious combination: heart disease, diabetes, obesity, and metabolic problems all together. These three groups were clearly different from each other, suggesting that diseases don’t develop randomly but follow specific patterns. Age was a major factor—each additional year of age increased the chances of being in the cholesterol or heart-disease groups. Women were significantly more likely than men to be in both the cholesterol group (2.5 times more likely) and the heart-disease group (3.4 times more likely).

Several other important patterns emerged. People who exercised regularly and slept 8 or more hours per night were less likely to have the serious heart-disease group of conditions. Surprisingly, having a very high income was actually associated with higher risk of both the cholesterol and heart-disease groups, possibly because wealthier people may have more sedentary lifestyles or different eating patterns. People who were employed had lower risk of the heart-disease group compared to unemployed people. Eating more food (higher dietary intake) was linked to higher cholesterol problems, which makes sense since diet affects cholesterol levels.

This study builds on previous research showing that chronic diseases tend to cluster together rather than occurring randomly. Earlier studies looked at multimorbidity one disease at a time, but this research uses a more sophisticated approach to reveal the actual patterns. The finding that women have higher rates of multiple diseases aligns with other research, though the reasons aren’t completely clear. The protective effects of exercise and adequate sleep confirm what many other studies have shown. The surprising finding about high socioeconomic status increasing disease risk differs from some previous research and suggests that wealth alone doesn’t guarantee health—lifestyle choices matter more.

This study has several important limitations to consider. First, it only looked at people at one point in time, so we can’t prove that the risk factors actually cause the diseases. Second, it was conducted in Iran, so the results may not apply exactly the same way to people in other countries with different genetics, healthcare systems, and lifestyles. Third, the study relied on people reporting their own health conditions, which might not be completely accurate. Fourth, the study couldn’t explain why high income increased disease risk—this unexpected finding needs more research to understand. Finally, the study didn’t look at all possible chronic diseases, only 11 specific ones, so other disease patterns might exist that weren’t captured.

The Bottom Line

Based on this research, here are evidence-based steps you can take: (1) Exercise regularly—the study shows this reduces risk of multiple diseases (moderate confidence). (2) Aim for 8+ hours of sleep per night—this was protective against serious disease combinations (moderate confidence). (3) Pay special attention to cholesterol levels and heart health, especially if you’re over 50 or female (moderate confidence). (4) Maintain a healthy diet and avoid overeating, as higher food intake was linked to cholesterol problems (moderate confidence). (5) If possible, stay employed or engaged in regular activities, as this was protective (low to moderate confidence). These recommendations are based on associations found in this study, not proven cause-and-effect relationships.

This research is especially important for: women over 50, people with family histories of heart disease or diabetes, people with high cholesterol, and anyone concerned about preventing multiple chronic diseases. Healthcare providers should pay attention to these disease clusters when treating patients. Public health officials in countries similar to Iran should consider these patterns when designing prevention programs. However, people living in very different countries or climates may need to adapt these findings to their own situations. If you have existing health conditions, talk to your doctor before making major lifestyle changes.

Don’t expect overnight results. Research suggests that lifestyle changes like exercise and better sleep take weeks to months to show measurable health improvements. Cholesterol levels might improve within 4-8 weeks of diet and exercise changes. However, preventing multiple diseases from developing is a long-term commitment—think in terms of months and years, not days and weeks. The good news is that these changes often make you feel better (more energy, better sleep) within days to weeks, even before health markers improve.

Want to Apply This Research?

  • Track three key metrics weekly: (1) Exercise minutes per week (aim for 150+ minutes), (2) Average sleep duration per night (aim for 8 hours), (3) Cholesterol-related foods consumed (high-fat, fried foods, processed meats). Create a simple weekly scorecard showing how many days you hit your targets.
  • Start with one small change: commit to 30 minutes of walking or light exercise 3 days per week for the next month. Use the app to set reminders and log your activity. Once this becomes a habit, add a second goal: going to bed 30 minutes earlier to increase sleep. These two changes alone showed protective effects in the study.
  • Set up monthly check-ins where you review your exercise, sleep, and dietary patterns. Track any changes in how you feel (energy levels, mood, sleep quality). Every 3-6 months, if possible, get your cholesterol checked to see if your lifestyle changes are working. Use the app to create a long-term trend chart showing your progress over 6-12 months.

This research describes patterns found in a specific population in Iran and cannot be used to diagnose or treat any medical condition. The findings show associations, not proven cause-and-effect relationships. If you have concerns about multiple chronic diseases, high cholesterol, heart disease, or any other health condition, please consult with your healthcare provider before making significant lifestyle changes. This information is for educational purposes only and should not replace professional medical advice. Women who are pregnant, people with existing serious health conditions, and those taking medications should especially consult their doctor before starting new exercise programs or making major dietary changes.