Markos Klonizakis

Dr. Markos Klonizakis


Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 December 2012 in BMJ
Verified
Journal Article
Open access
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THTania B Huedo-Medina
Tania B Huedo-Medina
IKIrving Kirsch
Irving Kirsch
JMJ. Middlemass
J. Middlemass
MKMarkos Klonizakis
Markos Klonizakis
ANAloysius Niroshan
Aloysius Niroshan
Objectives To investigate the effectiveness of non-benzodiazepine hypnotics (Z drugs) and associated placebo responses in adults and to evaluate potential moderators of effectiveness in a dataset used to approve these drugs. Design Systematic review and meta-analysis. Data source US Food and Drug Administration (FDA). Study selection Randomised double blind parallel placebo controlled trials of currently approved Z drugs (eszopiclone, zaleplon, and zolpidem). Data extraction Change score from baseline to post-test for drug and placebo groups; drug efficacy analysed as the difference of both change scores. Weighted raw and standardised mean differences with their confidence intervals under random effects assumptions for polysomnographic and subjective sleep latency, as primary outcomes. Secondary outcomes included waking after sleep onset, number of awakenings, total sleep time, sleep efficiency, and subjective sleep quality. Weighted least square regression analysis was used to explain heterogeneity of drug effects. Data synthesis 13 studies containing 65 separate drug-placebo comparisons by type of outcome, type of drug, and dose were included. Studies included 4378 participants from different countries and varying drug doses, lengths of treatment, and study years. Z drugs showed significant, albeit small, improvements (reductions) in our primary outcomes: polysomnographic sleep latency (weighted standardised mean difference, 95% confidence interval −0.57 to −0.16) and subjective sleep latency (−0.33, −0.62 to −0.04) compared with placebo. Analyses of weighted mean raw differences showed that Z drugs decreased polysomnographic sleep latency by 22 minutes (−33 to −11 minutes) compared with placebo. Although no significant effects were found in secondary outcomes, there were insufficient studies reporting these outcomes to allow firm conclusions. Moderator analyses indicated that sleep latency was more likely to be reduced in studies published earlier, with larger drug doses, with longer duration of treatment, with a greater proportion of younger and/or female patients, and with zolpidem. Conclusion Compared with placebo, Z drugs produce slight improvements in subjective and polysomnographic sleep latency, especially with larger doses and regardless of type of drug. Although the drug effect and the placebo response were rather small and of questionable clinical importance, the two together produced to a reasonably large clinical response.

1 November 2011 in Microvascular Research
Verified
Journal Article
Closed access
GTGarry Tew
Garry Tew
MKMarkos Klonizakis
Markos Klonizakis
HCHelen Crank
Helen Crank
JBJ. David Briers
J. David Briers
GHGary J. Hodges
Gary J. Hodges

1 October 2014 in Menopause
Verified
Journal Article
Closed access
MKMarkos Klonizakis
Markos Klonizakis
JMJames Moss
James Moss
SGStephen Gilbert
Stephen Gilbert
DBDavid Broom
David Broom
JFJeff Foster
Jeff Foster
GTGarry Tew
Garry Tew
This study compared the effects of a 2-week program of low-volume high-intensity interval training (HIT) with the effects of higher-volume moderate-intensity continuous training (CT) on cardiopulmonary and vascular functions in postmenopausal women. Twenty-two postmenopausal women were randomly assigned to undertake six HIT (n = 12) or CT (n = 10) sessions for 2 weeks. HIT sessions consisted of ten 1-minute intervals of cycling exercise at 100% of peak power output separated by 1 minute of active recovery. CT sessions involved 40 minutes of continuous cycling at 65% of peak power output. Variables assessed at baseline and 2 weeks included cardiopulmonary function (ventilatory threshold, peak oxygen uptake), macrovascular endothelial function (flow-mediated dilation of the brachial artery), and microvascular function (reactive hyperemia and local thermal hyperemia of forearm skin). Eighteen participants completed the study (HIT, 11; CT, 7). Adherence to the exercise programs was excellent, with 107 of 108 sessions completed. Despite substantially lower total time commitment (∼2.5 vs. ∼5 h) and training volume (558 vs. 1,237 kJ) for HIT versus CT, increases from baseline in peak oxygen uptake achieved significance (P = 0.01) for the HIT group only (Δ = 2.2 mL kg min; P for interaction = 0.688). Improvements in exercise test duration were observed in both groups (HIT, 13%; CT, 5%; P for interaction = 0.194). There were no significant changes in macrovascular or microvascular function in either group. The findings suggest that low-volume HIT is feasible and can lead to rapid improvements in cardiopulmonary function in postmenopausal women.

1 March 2011 in Microvascular Research
Verified
Journal Article
Closed access
GTGarry Tew
Garry Tew
MKMarkos Klonizakis
Markos Klonizakis
JMJames Moss
James Moss
ARAlan D. Ruddock
Alan D. Ruddock
JSJohn M. Saxton
John M. Saxton
GHGary J. Hodges
Gary J. Hodges

21 January 2013 in Clinical Science
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Journal Article
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MKMarkos Klonizakis
Markos Klonizakis
Ahmad AlkhatibAhmad Alkhatib
Ahmad Alkhatib
GMGeoff Middleton
Geoff Middleton
MSMark F. Smith
Mark F. Smith
The aging effect on microvascular integrity, marked by endothelial dysfunction and reduction in exercise tolerance, is a major cause of CVD (cardiovascular disease). Improved dietary habits, known to reduce morbidity and mortality, are also known to attenuate those aging effects. The present study investigated the effects of combined MD (Mediterranean diet) and exercise intervention on lower- and upper-limb cutaneous microvascular functions in an older healthy population. A total of 22 sedentary healthy participants (age, 55±4 years) underwent cardiopulmonary exercise tolerance test, and were assessed for their upper- and lower-limb vascular endothelial CVC (cutaneous vascular conductance) using LDF (laser Doppler fluximetry) with endothelium-dependent [ACh (acetylcholine chloride)] and -independent [SNP (sodium nitroprusside)] vasodilation. Participants were then randomized into two groups: MD and non-MD, and followed an 8-week intervention programme, which included discontinuous treadmill running based on each individual's exertion, twice per week. Exercise training improved CVC in both groups (e.g. 0.42±0.19 compared with 1.50±1.05 and 0.47±0.26 compared with 1.15±0.59 at 1000 μCb for MD and non-MD respectively; P<0.001). This was also combined by improvement in the exercise tolerance indicated by increased VT (ventilatory threshold) in both groups [12.2±2.8 compared with 14.8±2.8 ml·(kg of body weight)−1·min−1 and 11.7±2.7 compared with 14.6±3.2 ml·(kg of body weight)−1·min−1 for MD and non-MD groups respectively; P<0.05]. However, the MD group showed greater improvement in endothelium-dependent vasodilation than non-MD [ANCOVA (analyses of co-variance), P=0.02]. The results of the present study suggest that compliance with MD, combined with regular moderate exercise, improves age-provoked microcirculatory endothelial dysfunction and increases exercise tolerance, both responsible for reducing cardiovascular risk in this age group.

1 December 2015 in The Journal of nutrition, health and aging
Verified
Journal Article
Open access
PDF file
GMGeoff Middleton
Geoff Middleton
RKR. Keegan
R. Keegan
MSM. F. Smith
M. F. Smith
Ahmad AlkhatibAhmad Alkhatib
Ahmad Alkhatib
MKMarkos Klonizakis
Markos Klonizakis
To examine the participant experiences regarding perceived barriers and facilitators which impact on consuming the Mediterranean diet in the East of England. Qualitative methodology with focus groups. A healthy, middle-aged population situated in the East of England. Intervention: An 8-week Mediterranean dietary intervention trial. Eleven participants (including three co-habiting partners) in three focus groups, ranging between 50-65yrs with a mean age of 54.3yrs (±4.0) Thematic analysis from the focus groups revealed that participants considered that the MD intervention had introduced a better quality of food, widening the food-horizon and allowed them to re-define cultural eating habits. They also reported several physical benefits from adapting to this diet and found the experience as positive. Whilst claiming that the MD was an enjoyable and pleasurable, the participants did express difficulty adapting to the eating pattern, finding difficulty in purchasing food items, an increase in food costs and found work, stress and time pressures undermining adherence. The participants’ experiences suggested that the MD was an encouraging dietary change with a middle aged non-Mediterranean based population group. Future MD interventions should tailor interventions and support participants closely, particularly with the necessary planning, organisation and purchasing involved with implementing this diet in non-Mediterranean countries. Secondly, researchers should also challenge any erroneous assumptions regarding the consumption of Mediterranean food, which may hinder implementation.