Recent evidence suggests a link between periodontitis (PD) and hypertension, but the nature of this association remains unclear. The overall aim of this review was to critically appraise the evidence linking these two common disorders. Systematic search was conducted for studies published up to December 2018. Prevalence of hypertension in patients with PD (moderate/severe groups) vs. those without PD (non-PD) was the primary outcome. Additional outcomes included adjusted mean difference in systolic (SBP) and diastolic (DBP) blood pressure (BP) levels in PD vs. non-PD, assessment of biomarkers in PD and hypertension, and BP changes after periodontal therapy. From 81 studies selected, 40 were included in quantitative meta-analyses. Diagnoses of moderate-severe PD [odds ratio (OR) = 1.22; 95% confidence interval (CI): 1.10–1.35] and severe PD (OR = 1.49; 95% CI: 1.09–2.05) were associated with hypertension. Prospective studies confirmed PD diagnosis increased likelihood of hypertension occurrence (OR = 1.68; 95% CI: 0.85–3.35). Patients with PD exhibited higher mean SBP [weighted mean difference (WMD) of 4.49 mmHg; 95% CI: 2.88–6.11] and DBP (2.03 mmHg; 95% CI: 1.25–2.81) when compared with non-PD. Lastly, only 5 out of 12 interventional studies confirmed a reduction in BP following periodontal therapy, ranging from 3 to 12.5 mmHg of SBP and from 0 to 10 mmHg of DBP. PD is associated with increased odds of hypertension (SORT C) and higher SBP/DBP levels. The evidence suggesting that PD therapy could reduce BP is inconclusive. Although additional research is warranted on this association, these results suggest that oral health assessment and management of PD could not only improve oral/overall health and quality of life but also be of relevance in the management of patients with hypertension.

Design: Subjects were studied at baseline and during local leg infusion of insulin alone (control, n ϭ 7) or insulin plus the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA, n ϭ 7) to prevent insulin-induced vasodilation. Methods: We measured skeletal muscle protein metabolism with stable isotope tracers, blood flow with indocyanine green, capillary recruitment with contrast enhanced ultrasound, glucose metabolism with stable isotope tracers, and phosphorylation of proteins associated with insulin (Akt) and amino acid-induced mammalian target of rapamycin(mTOR) complex 1 (mTORC1) signaling (mTOR, S6 kinase 1, and eukaryotic initiation factor 4Ebinding protein 1) with Western blot analysis. Results: No basal differences between groups were detected. During insulin infusion, blood flow and capillary recruitment increased in the control (P Ͻ 0.05) group only; Akt phosphorylation and glucose uptake increased in both groups (P Ͻ 0.05), with no group differences; and mTORC1 signaling increased more in control (P Ͻ 0.05) than in L-NMMA. Phenylalanine net balance increased (P Ͻ 0.05) in both groups, but with opposite mechanisms: increased protein synthesis (basal, 0.051 Ϯ 0.006%/h; insulin, 0.077 Ϯ 0.008%/h; P Ͻ 0.05) with no change in proteolysis in control and decreased proteolysis (P Ͻ 0.05) with no change in synthesis (basal, 0.061 Ϯ 0.004%/h; insulin, 0.050 Ϯ 0.006%/h; P value not significant) in L-NMMA. Conclusions: Endothelial-dependent vasodilation and the consequent increase in nutritive flow and mTORC1 signaling, rather than Akt signaling, are fundamental mechanisms by which insulin stimulates muscle protein synthesis in humans. Additionally, these data underscore that insulin modulates skeletal muscle proteolysis according to its effects on nutritive flow. Dihydrotestosterone Suppresses Foam Cell Formation and Attenuates Atherosclerosis DevelopmentYang Qiu, Toshihiko Yanase, Haidi Hu, Tomoko Tanaka, Yoshihiro Nishi, Min Liu, Katsuo Sueishi, Tatsuya Sawamura, and Hajime Nawata ABSTRACTThe role of testosterone in atherosclerosis remains unclear because it is aromatized to estrogen. We investigated the effect of the nonaromatized natural androgen 5␣-dihydrotestosterone (DHT) on the rabbit atherogenesis in relation to the proatherogenic molecule lectin-like oxidized-low-density lipoprotein receptor-1 (LOX-1) and its downstream molecules. Thirty-nine male New Zealand white rabbits were divided into four groups: 1) noncastrated group with normal chow diet (n ϭ 6); 2) noncastrated group with high-cholesterol diet (HCD) (n ϭ 10); 3) castrated group with HCD plus sc placebo pellet (n ϭ 11); and 4) castrated group with HCD plus sc 150 mg DHT pellet (n ϭ 12). Implantation of sc DHT or placebo pellet was performed at the time of castration. After castration or sham operation, the rabbits were fed the HCD for 8 wk, and plaque areas were assessed in the entire aorta. The HCD-induced increase in plaque area, which was most aggravated in the castration plus placebo group, was attenuated in the castration p...

Prolactin (PRL) is tonically inhibited by dopamine (DA) released from neurons in the arcuate and periventricular nuclei. Kisspeptin plays a pivotal role in LH regulation. In rodents, kisspeptin neurons are found mostly in the anteroventral periventricular and arcuate nuclei, but the physiology of arcuate kisspeptin neurons is not completely understood. We investigated the role of kisspeptin in the control of hypothalamic DA and pituitary PRL secretion in adult rats. Intracerebroventricular kisspeptin-10 (Kp-10) elicited PRL release in a dose-dependent manner in estradiol (E2)-treated ovariectomized rats (OVX+E2), whereas no effect was found in oil-treated ovariectomized rats (OVX). Kp-10 increased PRL release in males and proestrous but not diestrous females. Associated with the increase in PRL release, intracerebroventricular Kp-10 reduced Fos-related antigen expression in tyrosine hydroxylase-immunoreactive (ir) neurons of arcuate and periventricular nuclei in OVX+E2 rats, with no effect in OVX rats. Kp-10 also decreased 3,4-dihydroxyphenylacetic acid concentration and 3,4-dihydroxyphenylacetic acid-DA ratio in the median eminence but not striatum in OVX+E2 rats. Double-label immunofluorescence combined with confocal microscopy revealed kisspeptin-ir fibers in close apposition to and in contact with tyrosine hydroxylase-ir perikarya in the arcuate. In addition, Kp-10 was not found to alter PRL release from anterior pituitary cell cultures regardless of E2 treatment. We provide herein evidence that kisspeptin regulates PRL release through inhibition of hypothalamic dopaminergic neurons, and that this mechanism is E2 dependent in females. These findings suggest a new role for central kisspeptin with possible implications for reproductive physiology.

Prolactin (PRL) secretion is inhibited by hypothalamic dopamine. Kisspeptin controls luteinising hormone (LH) secretion and is also involved in PRL regulation. We further investigated the effect of kisspeptin-10 (Kp-10) on the activity of tuberoinfundibular dopaminergic (TIDA) neurones and the role of oestradiol (E2 ) in this mechanism. Female and male rats were injected with i.c.v. Kp-10 and evaluated for PRL release and the activity of dopamine terminals in the median eminence (ME) and neurointermediate lobe of the pituitary (NIL). Kp-10 at the doses of 0.6 and 3 nmol increased plasma PRL and decreased 4-dihydroxyphenylacetic acid (DOPAC) levels in the ME and NIL of ovariectomised (OVX), E2 -treated rats but had no effect in OVX. In gonad-intact males, 3 nmol Kp-10 increased PRL secretion and decreased DOPAC levels in the ME but not in the NIL. Castrated males treated with either testosterone or E2 also displayed increased PRL secretion and reduced ME DOPAC in response to Kp-10, whereas castrated rats receiving oil or dihydrotestosterone were unresponsive. By contrast, the LH response to Kp-10 was not E2 -dependent in either females or males. Additionally, immunohistochemical double-labelling demonstrated that TIDA neurones of male rats contain oestrogen receptor (ER)-α, with a higher proportion of neurones expressing ERα than in dioestrous females. The dopaminergic neurones of periventricular hypothalamic nucleus displayed much lower ERα expression. Thus, TIDA neurones express ERα in male and female rats, and kisspeptin increases PRL secretion through inhibition of TIDA neurones in an E2 -dependent manner in both sexes. These findings provide new evidence about the role of kisspeptin in the regulation of dopamine and PRL.