BP levels among U.S. adults with diabetes improved between 1988–1994 and 2001–2008. There was no evidence of any improvement among adults aged 20–44 years. Virtually all of the improvements were limited to the 1990s, and no significant improvements were seen in the 2000s.
The improvement in BP levels, in conjunction with prior reported improvement in A1C levels (9
), may indicate encouraging trends in diabetes management. Indeed, despite upward hypertension prevalence, which may be driven in part by rising obesity (10
), BP levels improved, indicating probably more effective hypertension management. During our study period, landmark clinical trials showed that BP control reduced vascular complications (3
) and new clinical guidelines lowered BP targets to <130/80 mmHg (11
). Awareness of the benefits of BP control may have increased and treatment intensified. Furthermore, the lowered BP target might have resulted in earlier diagnosis and treatment at lower BP levels, contributing not only to the observed increase in hypertension prevalence but also to increased awareness, treatment, and control rates.
The lack of improvement among young adults is concerning because of their future risk of developing vascular complications at younger ages. Several factors could explain the poor levels of control in younger patients, including a lower adherence to medications (13
); a lower tendency to receive treatment intensification (14
); and less optimal care for hypertension, i.e., delayed initiation of pharmacotherapy when lifestyle intervention fails (15
Limitations of our study include the relative small sample sizes for young adults, which may limit our ability to detect small changes. BP measurement errors may also exist since BP was measured at a single occasion in the NHANES. However, the methods were consistent across all NHANES and BP levels were based on averaged readings.
Finally, we found that the progress in BP levels in the adult population with diabetes may have stalled in 2000s. Although hypertension awareness and treatment rates are now high (~90%), hypertension prevalence remains high and control rates are suboptimal, indicating need for effective prevention and control strategies.