Studies Flashcards
DPP
https://www.niddk.nih.gov/about-niddk/research-areas/diabetes/diabetes-prevention-program-dpp
• Population 3.2K ppl, mixed races almost half and half white vs ethnic
• Longitudinal/randomised controlled? All those at risk diabetes. 3y
• Intervention: Lifestyle vs nothing (normal advice) vs Metformin BD
• Lifestyle programme = 58% red, Metformin 31% reduc
• Lifestyle = lose 7% bodyweight via diet and exercise
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Jenkins portfolio Diet
1m fy
Plant sterols (fortified or avocado etc), unsat fat (nus – almonds, cashew, hazelnut), soy protein, soluble fibre (veg, legumes, fruit – black beans, avocado, chia seeds)
• Normal diet (low sat fat, low full fat diary = 8% red LDL
• Normal Diet + low dose statin = 31%
• Porfolio diet: 29%
*Like 50 participants – did they do other interventions too and did they lose weight? This is for cholesterol Mediterranean diet better for heart disease
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Lifestyle Heart Trial
Topic: looking at feasibility and effect of lifestyle changes over 5 years on CHD progression
Randomized control trial, single blinded – radiologists only
P: 48 adults with moderate to severe CHD
Intervention: Intensive lifestyle changes including low fat (10% of calories) diet, vegetarian, aerobic exercise, smoking cessation, stress reduction, group psychosocial support
Controls: Normal Dr’s lifestyle recommendations via AHA Step 2 diet (<30% energy from fat, <7% sat fat)
Outcome:
In the experimental group there was a dose response association between adherence and regression of atherosclerotic stenosis
• Reduction in cardiac events 45 vs 25 (MI, Bypass, death,
• Regression of stenoses in experimental group – 7.1% vs worsening 27.7% in controls (47% in group not taking lipids) – none of experimental group took lipids
• Continued reduction stenoses at 1 and 5 years
• Dec LDL, 40% (37.2) at 1 year, 20% at 5 years
• 91% reduction in freq angina vs 165% ^ in controls
• Controls:
o ^ angina 165%
o ^ stenosis % diameter 42>46%
o 2x as many cardiac events
Limitations
• Half subjects declined
• 27% drop out rate at 5 year fu – although no bias in pop drop out rate and equal amongst group
Conclusions
• Comprehensive lifestyle changes can = significant reductions in LDL and angina and CHD progression
PCI Compared with Exercise Training in stable CAD
Objective: Can stable CAD patients improve myocardial perfusion and disease progression with exercise and what is it in comparison to PCI with stenting on:
• Clinical symptoms
• Angina free exercise capacity
• Myocardial perfusion
• Cost (average expense to ^ Canadian Cardiovascular Society Class by 1 class)
P: 101 males aged 70 or > with stable CAD nad one naïve artery >75% stenosed
I: 20mins bike ergometry/day
C: PCI
O:
• ^ event free survival 88 vs 70%
• ^ exercise capacity tolerance (^20%)
• ^max o2 uptake (+16%)
• ^ ischaemic threshold 30%
• ^HDL (0.1) – (LDL unchanged)
• Lower cost - double
• Reduced hosp
• Reduced re-vascularisations
PCI group ^ exercise tolerance and ischaemic threshold
Key Conclusion:
^exercise tolerance, max o2 uptake, ischaemic threshold, at a lower cost
Limitations: 2 in each group terminated
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MRFIT Study
• People with low risk factor status had
o 73-85% lower risk for CVD mortality
o 40-60% lower total mortality ate
o 6-10 y ^ life expectancy
Framingham Heart Study
• 1948 started Prospective/longitudinal risk of atherosclerotic risk in ppl free of CVD at age 50
• Wanted to identify RF’s contributing to CVD over time – since spanned 3 generations
• Cholesterol (LDL), HTN!
• Men with optimal risk 5% lifetime risk atherosclerotic CVD vs men with 2 + RF’s = 69% risk.
at 50 median 10year longer life, 11 men, 8 women) Also 10y longer life expectancy compared to latter
What about FH – so later used offspring to review FH, also he population is white middle class, so later used ethnics (Omni)
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Chicago Heart Association Detection Project Industry
• Heart Disease risk determined by nos of cardiac RF’s.
• People with lower RF’s in middle age = better QOL and lower medicare costs
INTERSTROKE STUDY
• Prospective case control study
• 20k people
• RFs for stroke were similar to INTERHEART
o Metabolic syndrome (incl abdo obesity specifically)
o Add cardiac causes
• 10 RFs = 90% of risk
INTERHEART STUDY
• Case control study 25k v 15k
• Patients admitted to cardiac care for 1st MI vs matched controls ie attendants or relatives)
• 52 countries
• Reviewed 9 worldwide RF’s
o Smoking
o Obesity
o Diet
o HTN
o Exercise
o Alcohol
o Diabetes
o Lipids
o Psychosocial/Stress
• Factored for confounding of country, race, gender,
• 80% of risk = metabolic syndrome (Lipids, HTN, obesity, DM) + smoking = 80% pop attributable risk
• 9 RF’s = 90% risk in men, 94% in women
• Smoking, HTN, DM ^ risk by odds ratio 13:1
Is the reverse true?
What about other RFs incl socio-economic class etc
Comparison of Diets for Weight Loss and Heart Disease Reduction
Objective/Aims: Compare effects of 4 popular diets – on weight and CVD risk factors
- Atkins: Low Carb - Ornish: Low fat, plant based - Weight Watchers: Calorie Restriction - Zone Diet: Macros lean protein 40%, low GI carbs30 fat (^unsat) 30%
Study Design: Randomised control trial
Population: 160 overweight or obese
Intervention: 40 people assigned to each diet
Key Results
All 4 diets resulted in moderate levels weight loss at 1 year, no statistically significant differences between diets
• Weight loss was related to adherence regardless of which diet – weight loss associated wth adherence NOT diet type
• 10% reduction in LDL:HDL ratio
• All diets resulted in decrease in total chol: HDL ratio, crp, insulin
• No significant effects on glucose or BP
GEMINAL STUDY
P: 30 men with low-risk prostate cancer
I: 3 months – 3d intense residential retreat then weekly O/P contact – whilst undergoing surveillance for tumour progression
• Low fat <10%), wholefood, plant based diet
• Supplemented wih soy, selenium, fish oil, Vit E, C and selenium
• 60mins stress Mx ie yoga
• Aerobic exercise e- 60m walking 6d/week
• Weekly 1 hr support session
C: single arm pilot intervention study
O: Weight, abdominal obesity , BP and lipid profile
Limitations
• Small study
• Only low risk tumours
• Couldn’t match pre and post tumour saples
• Loads of initial pop lost, ie declined
Conclusions
?intensive lifestyle changes can modulate prostate gene expression
Reversal of Type 2 Diabetes
Population:
Intervention Group: 11 people with diabetes on VLCD
Control Group: 9 ppl non diabetic matched weight, age, sex
Intervention: 600 calorie/day diet studied 1, 4, 8 weeks. Statins cont
Outcome: Diet restriction = ing better beta cell func and insulin sensitivity and dec panc & liver fat stores
Key results
• Fasting glucose normalized in diabetic group from 9 »_space;5,9
• Insulin resistance and response improved (response towards control values)
• Hepatic TF and Pancreatic TG dec (12.8 and 8 respectively)
DASH diet for HTN (high impact)
DASH diet for HTN (high impact)
• Population: 459 – various BP’s, <160 systolic and 80-95 dia
• Randomised control
• Intervention: (8 weeks)
o control diet (US typical, low fibre, high sat fat etc),
o Rich in fruit and veg diet 2.8/1.1
o Combo diet: prev, also low fat diary, low sat fat, and total fat – 5/3 (11.4/5.5 for those with HTN)
• Reduction in BP started within 2w
• in subjects with hypertension and in those without hypertension, the combination diet reduced blood pressure more than the fruits-and-vegetables or the control diet
• ?as good as drug monotherapy
• Limitations: duration/adherence, weight?
• Add low sodium too and wow!
Lyon Diet Heart Study (High Impact)
Med diet: fruit, veg, olive oil, poultry and fish, less red meat
• P: 605 post MI split into experimental or control group
• Randomised control trial
• Mediterranean alpha-linolenic acid-rich vs controls ? or normal/not meeting AHA Step I diet guidelines (<30% of calories from fat, 8% to 10% from saturated fat, and <300 mg/d cholesterol; Tab
• 4 years fu
• Outcome: Fewer CVD outcomes in Med group: MI 14 vs 44, other (PE, HF, unstable angina) 27 vs 90 CO3 was minor hospitalisation events
The Esselstyn plant-based diet for coronary artery disease (seminal) 71,72(seminal study for lifestyle medicine)
a)A very low-fat, plant-based diet was shown to reverse and prevent major cardiac events in 177 adherent patients over 3.7 years. Among the 177 adherent patients, cardiac event rates were 0.6%. Among the 21 non-adherent patients, 13 experienced major cardiac events (62%).
