Chronomedicine: a necessary concept to manage human diseases

Recent advances in circadian-regulated pharmacokinetics and its implications for chronotherapy

Dependence of pharmacokinetics and drug effects (efficacy and toxicity) on dosing time has long been recognized. However, significant progress has only recently been made in our understanding of circadian rhythms and their regulation on drug pharmacokinetics, efficacy and toxicity. This review will cover the relevant literature and a series of publications from our work summarizing the effects of circadian rhythms on drug pharmacokinetics, and propose that the influence of circadian rhythms on pharmacokinetics are ultimately translated into therapeutic effects and side effects of drugs. Evidence suggests that daily rhythmicity in expression of drug-metabolizing enzymes and transporters necessary for drug ADME (absorption, distribution, metabolism and excretion) are key factors determining circadian pharmacokinetics. Newly discovered mechanisms for circadian control of the enzymes and transporters are covered. We also discuss how the rhythms of drug-processing proteins are translated into circadian pharmacokinetics and drug chronoefficacy/chronotoxicity, which has direct implications for chronotherapy. More importantly, we will present perspectives on the challenges that are still needed for a breakthrough in translational research. In addition, knowledge of the circadian influence on drug disposition has provided new possibilities for novel pharmacological strategies. Careful application of pharmacokinetics-based chronotherapy strategies can improve efficacy and reduce toxicity. Circadian rhythm-mediated metabolic and transport strategies can also be implemented to design drugs.

Perioperative Blood Loss Can Be Reduced If Total Knee Arthroplasty Was Performed in the Si Hour-Period, Compared with the Wei Hour-Period: A Retrospective Cohort Study

OBJECTIVE

To investigate the efficacy and safety of performing primary unilateral total knee arthroplasty (TKA) in the "Si hour-period" meaning 09:00 a.m. to 11:00 a.m. (one of the 12 two-hour periods into which the day was traditionally divided, each being given the name of one of the 12 earthly branches), compared with the "Wei hour-period" (13:00-15:00).

METHODS

Patient documentations were studied for those who underwent a primary unilateral TKA performed by the same surgical team with a tourniquet between January 2018 and January 2021 at our medical center. Eighty-four patients were enrolled and assigned into group A (in Si hour-period) and group B (in Wei hour-period). The main outcomes were total blood cell loss (TBL), hidden blood loss (HBL), visible blood loss (VBL), maximum hemoglobin (Hb) drop, and transfusion rate. Secondary outcomes were length of hospital stay (LOS), postoperative femorotibial mechanical axis (FTMA), FTMA correction, platelet count, plasma D-dimer (D-D), prothrombin time (PT), international normalized ratio (INR), and the incidence of postoperative complications.

RESULTS

Group A showed statistical significance lower at the mean TBL, the mean HBL, and the maximum Hb drop (95% CI: -352.8 to -46.1,P=0.011, 95% CI: -348.0 to -40.1,P=0.014, and 95% CI: -9.5 to -0.7,P=0.023, respectively) after TKA than group B. The postoperative platelet count of group A was more significant than that of group B (95% CI:3.1 to 52.9, P=0.028). The VBL, transfusion rate, the LOS, postoperative FTMA, FTMA correction, plasma D-D, PT, INR, and the incidence of postoperative complications (wound complications, calf muscular vein thrombosis, infection, pulmonary embolism, and deep vein thrombosis) were similar between the two groups (P > 0.05, respectively).

CONCLUSION

Our study shows that blood loss can be reduced when TKA is performed in the "Si hour-period," which may be due to increasing platelet count, and postoperative complications did not increase, compared with the Wei hour-period. We recommend that the selective operation, such as TKA, should be performed in the "Si hour-period" in clinical practice between the two hour-period.

Change is the Only Constant in Life (and in Sleep Medicine)

ABSTRACT

Heraclitus, a philosopher who lived nearly 500 years before the common era, made the assertion that "Life is Flux," meaning that change is the only constant in life. Modern medicine, inclusive of the field of sleep medicine, has undergone dramatic changes over the last 10 years. For the American Academy of Sleep Medicine (AASM) specifically, the last year has been one of great change. Yes, change happens, but with great change comes even greater opportunity. As AASM president, I have been focused on staying abreast of the changes in our health care system while anticipating and preparing to adapt to challenges in our field. In June 2017, given all the changes in our health care delivery system, I challenged the AASM membership and our field to adapt our models of care to reduce the number of patients with undiagnosed and untreated obstructive sleep apnea (OSA) by 10% over 5 years. This article will provide a brief update describing how the AASM board of directors has responded to my challenge and capitalized on change in the areas of the physician pipeline, patient access, advocacy, new technology and strategic research. Change is inevitable and often beyond our control, but how we anticipate and respond to change is entirely within our power. As sleep specialists, it is our responsibility not only to respond to change so that we can deliver the best possible care for our patients, but also to be the leading voice for change so that we all achieve better health through optimal sleep.