Introduction:
Insomnia is a highly prevalent sleep disorder known to independently affect the onset, course, and response to treatment for a number of psychiatric disorders. In particular, insomnia is associated with neuroendocrine stress system changes. Less is known about medical risks, though recent evidence implicates insomnia in hypertension, metabolic dysregulation, and inflammation. We hypothesized that insomnia is positively associated with hypertension and objectively-assessed risk factors.
Methods:
Data from the 2007-2008 NHANES (N=4,072) examined which risk factors were associated with insomnia symptoms and previous insomnia diagnosis. In addition to previous diagnosis, insomnia symptoms were sleep latency (mins), difficulty falling asleep, difficulty resuming sleep upon awakening, and early morning awakening. The latter three were coded as never, rarely, sometimes, often or almost always. Cardiometabolic risk factors included hypertension history, systolic and diastolic BP, pulse, and fasting triglycerides, cholesterol, insulin, glucose, HbA1c, and c-reactive protein (CRP). Weighted regression models explored relationships adjusted for age, sex, race/ethnicity, income, education, marital status, BMI, diet, exercise, and smoking.
Results:
Overall, a pattern emerged, such that all insomnia variables were associated with increased risk of hypertension. Further, diastolic BP, triglycerides, and HbA1c were all positively associated with several insomnia variables. Other risk factors (e.g., cholesterol, glucose, CRP) were only associated with one of the insomnia variables. See
Table
for specific results.
Conclusion:
Symptoms of insomnia were associated with hypertension and a number of objectively-assessed cardiometabolic risk factors, including some in domains not previously explored relative to insomnia (e.g., lipids, HbA1c). Future prospective studies will be needed to ascertain whether pre-existing insomnia is a risk factor for the onset of cardiometabolic dysfunction.
Associations between insomnia variables and cardiometabolic risk factors
Variable
β
SE
Previous Insomnia Diagnosis
Hypertension (OR) Systolic BP Diastolic BP Pulse Triglycerides (log) Cholesterol Insulin (log) Glucose (log) HbA1c (log) CRP (log)
**
3.027 1.888 0.036 0.502 0.993 1.504 1.001 0.973
***
0.966 1.000
1.067 2.315 1.515 1.182 0.102 6.561 0.111 0.022 0.009 0.173
Sleep Latency (Minutes)
Hypertension (OR) Systolic BP Diastolic BP Pulse Triglycerides (log) Cholesterol Insulin (log) Glucose (log) HbA1c (log) CRP (log)
***
1.008 0.011
†
0.019
*
0.029
*
1.001
*
0.093 1.001 1.000 1.000
*
1.003
0.002 0.015 0.011 0.012 0.001 0.042 0.001 0.0002 0.0001 0.001
Difficulty Falling Asleep (“Almost Always” vs “Never”)
Hypertension (OR) Systolic BP Diastolic BP Pulse Triglycerides (log) Cholesterol Insulin (log) Glucose (log) HbA1c (log) CRP (log)
*
2.076
†
2.111
***
2.804
†
1.585
**
1.115 4.426 1.054
*
0.969
*
0.987 1.107
0.394 1.168 0.841 0.935 0.043 3.400 0.079 0.015 0.006 0.088
Difficulty Resuming Sleep (“Almost Always” vs “Never”)
Hypertension (OR) Systolic BP Diastolic BP Pulse Triglycerides (log) Cholesterol Insulin (log) Glucose (log) HbA1c (log) CRP (log)
***
2.132 0.877
***
3.830 1.029
*
1.098 3.779 1.028 0.990
**
0.979 1.074
0.417 1.148 0.796 0.987 0.044 3.310 0.075 0.015 0.008 0.089
Early Morning Awakening (“Almost Always” vs “Never”)
Hypertension (OR) Systolic BP Diastolic BP Pulse Triglycerides (log) Cholesterol Insulin (log) Glucose (log) HbA1c (log) CRP (log)
**
1.817 1.645
*
2.205 0.252 0.996 0.030 0.995 0.974 0.988 1.039
0.361 1.256 0.928 1.058 0.040 3.460 0.085 0.016 0.009 0.091
†
p<0.10;
*
p<0.05;
**
p<0.01;
***
p<0.001
Estimating the cumulative risk of postnatal depressive symptoms: the role of insomnia symptoms across pregnancy
