Study links anxiety and poor sleep to heart and kidney disease progression

A pattern of restorative sleep is associated with a reduced likelihood of facing a cascade of chronic health conditions. A new large-scale analysis identifies a link between healthy sleep habits and a lower incidence of heart disease, kidney disease, and diabetes. The research also suggests that quality sleep is correlated with a decreased probability of these conditions advancing into a state where multiple diseases coexist.

The findings were published in Sleep Health: Journal of the National Sleep Foundation. This research highlights the significant relationship between lifestyle factors and the progression of chronic illness.

Medical professionals classify heart disease, type 2 diabetes, and chronic kidney disease under an umbrella term known as cardio-renal-metabolic diseases. These conditions often do not occur in isolation. Patients frequently develop one condition which then strains other bodily systems, leading to the development of a second or third disease.

The simultaneous presence of two or more of these conditions is called cardio-renal-metabolic multimorbidity. This state is associated with a much higher risk of premature death and significantly greater healthcare costs. Preventing the transition from a single disease to a cluster of diseases is a primary goal for public health officials.

Researchers from Zhengzhou University and Jilin University in China conducted this study to understand how sleep influences this disease progression. Previous investigations have typically examined the link between sleep and individual diseases in isolation. There has been less focus on how sleep patterns affect the trajectory from good health to a single disease and finally to multimorbidity.

The team also sought to understand the role of mental health in this process. Anxiety and depression are known to disrupt sleep and are also common in patients with chronic physical illnesses. The authors hypothesized that these psychological factors might act as a bridge connecting poor sleep to physical disease.

To investigate these relationships, the authors utilized data from the UK Biobank. This is a massive biomedical database containing genetic and health information from half a million participants in the United Kingdom. For this specific analysis, the researchers selected 375,837 participants.

The cohort was comprised of individuals aged 37 to 73 years. The participants were generally healthy at the start of the study period and did not have existing heart, kidney, or metabolic conditions. The researchers followed these individuals for a median period of nearly 14 years.

The study assessed sleep quality using a composite score based on six specific behaviors. These behaviors included sleep duration, chronotype (whether a person is a “morning” or “evening” person), and insomnia frequency. The score also accounted for snoring, daytime napping, and how easily participants woke up in the morning.

Participants received points for each healthy behavior. A healthy duration was defined as seven to eight hours per day. An early chronotype, lack of snoring, and rare insomnia were also scored positively. A higher total score indicated a healthier overall sleep profile.

The research team employed a statistical method known as a multistate model. This approach allowed them to track participants through different stages of health over time. They observed transitions from full health to a first diagnosis, and then from that first diagnosis to multimorbidity or death.

The results showed a clear protective benefit associated with high sleep scores. Participants with the healthiest sleep traits had a 30 percent lower risk of developing a first cardio-renal-metabolic disease compared to those with poor sleep scores. This suggests that good sleep acts as a shield against the initial onset of chronic illness.

The protective effect extended beyond the first diagnosis. Among those who did develop a first disease, healthy sleepers were 30 percent less likely to progress to multimorbidity. This finding implies that even after a diagnosis, maintaining good sleep habits may slow the deterioration of health.

The study also found a reduction in mortality risk. Healthy sleep traits were associated with a 21 percent lower risk of transitioning from a healthy state to death during the study period. This reinforces the connection between restorative rest and overall longevity.

When the researchers looked at specific diseases, the connection to type 2 diabetes was particularly strong. Healthy sleep habits showed a greater association with preventing diabetes than they did with preventing heart or kidney disease. This aligns with biological evidence linking sleep deprivation to insulin resistance and glucose metabolism issues.

The analysis of mental health factors provided additional insight into why these associations exist. The researchers found that anxiety and depression mediated a significant portion of the risk. Psychological distress explained approximately 16 percent of the relationship between sleep and the first disease diagnosis.

For the progression to multimorbidity, anxiety and depression accounted for about 14 percent of the risk. The mediation effect was strongest regarding mortality. Mental health factors explained roughly 25 percent of the link between sleep traits and death.

This suggests a bidirectional relationship where poor sleep fuels mental distress, which in turn stresses the cardiovascular and metabolic systems. Conversely, reducing anxiety and depression could be a key mechanism by which sleep improves physical health.

The researchers observed that the protective benefits of sleep were most evident in the early and middle stages of disease progression. Once a patient reached a state of severe multimorbidity, the impact of sleep on mortality was no longer statistically significant. This indicates that sleep interventions might be most effective before disease burden becomes overwhelming.

The study had a few distinct strengths in its design. The use of a composite sleep score provided a more comprehensive picture than looking at sleep duration alone. The large sample size and long follow-up period added weight to the statistical conclusions.

However, there are important caveats to consider when interpreting these results. The sleep data was self-reported by participants at the beginning of the study. Human memory can be imperfect, and sleep habits can change over more than a decade.

The study population also presents a limitation regarding generalizability. Over 95 percent of the participants in the UK Biobank are White. This lack of diversity means the findings may not fully apply to other racial or ethnic groups who might face different health disparities.

Additionally, the study is observational in nature. This means it can identify strong associations but cannot definitively prove that poor sleep causes these diseases. Unmeasured factors, such as specific genetic markers or environmental stressors, could influence the results.

Future research should aim to replicate these findings in more diverse populations. Studies that monitor changes in sleep patterns over time would also provide clearer data than a single baseline measurement. Clinical trials could help determine if improving sleep hygiene directly halts the progression of these diseases.

Despite these limitations, the study offers practical implications for preventative medicine. It suggests that screening for sleep problems should be a routine part of assessing cardiovascular and metabolic risk. Addressing sleep issues early could potentially delay or prevent the onset of complex, multi-system diseases.

The connection to mental health also suggests a need for holistic treatment. Managing anxiety and depression may be just as vital for heart and kidney health as monitoring blood pressure or blood sugar. Physicians might consider integrated approaches that target both sleep and mental well-being to protect physical health.

The study, “Sleep traits and the longitudinal progression of cardio-renal-metabolic multimorbidity: A prospective study from UK-Biobank,” was authored by Yali Niu, Tianrun Wang, Xiaocan Jia, Chaojun Yang, Jingwen Fan, Chenyu Zhao, Nana Wang, Zhixing Fan, and Xuezhong Shi.