Sleep modulates hypertension in leptin-deficient obese mice.
Leptin increases sympathetic activity, possibly contributing to hypertension in obese subjects. Hypertension increases cardiovascular mortality, with nighttime (sleep) blood pressure having a substantial prognostic value. We measured blood pressure in male leptin-deficient obese mice (ob/ob; n=7) and their lean wild-type littermates (+/+; n=11) during wakefulness, non-rapid-eye-movement sleep, and rapid-eye-movement sleep to investigate whether, in the absence of leptin, derangements of blood pressure are still associated with obesity and depend on the wake-sleep state. Mice were implanted with a telemetric pressure transducer and electrodes for discriminating wake-sleep states. Mean blood pressure was significantly higher in ob/ob than in +/+ mice during wakefulness (7.3+/-2.6 mm Hg) and non-rapid-eye-movement sleep (6.7+/-2.8 mm Hg) but not during rapid-eye-movement sleep (2.6+/-2.6 mm Hg). In ob/ob and +/+ mice, mean blood pressure was substantially higher during wakefulness than during non-rapid-eye-movement sleep. On passing from non-rapid-eye-movement sleep to rapid-eye-movement sleep, mean blood pressure decreased significantly in ob/ob but not in +/+ mice. The time spent during wakefulness was lower in ob/ob than in +/+ mice during the dark (active) period, whereas the opposite occurred during the light (rest) period. Consequently, mean blood pressure was significantly higher in ob/ob than in +/+ mice during the light (8.2+/-2.4 mm Hg) but not during the dark (3.0+/-2.9 mm Hg) period. These data suggest that, in the absence of leptin, obesity may entail hypertensive derangements of blood pressure, which are substantially modulated by the cardiovascular effects of the wake-sleep states.
Silvani
Alessandro
A
Department of Human and General Physiology, University of Bologna, Piazza di Porta San Donato 2, 40126 Bologna, Italy.
Bastianini
Stefano
S
Berteotti
Chiara
C
Franzini
Carlo
C
Lenzi
Pierluigi
P
Lo Martire
Viviana
V
Zoccoli
Giovanna
G
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D018389:Codon, Nonsense; D004195:Disease Models, Animal; D006973:Hypertension / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D020738:Leptin / Q000235:genetics*; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009765:Obesity / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D012890:Sleep / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology; D014851:Wakefulness / Q000502:physiology
D018389:Codon, Nonsense; D020738:Leptin