Key Articles

Question 1

According to McGinnis et al (JAMA 1993), what proportion of premature death in the US in 1990 can be attributed to external factors? What were the three leading causes?

Answer 1

Approximately 50% of all US deaths (1990) attributed to these factors:
3 leading causes: Tobacco, Diet/Activity patterns, Alcohol
Also microbial agents, toxic agents, firearms, sexual behaviour, motor vehicles, illicit use of drugs

Question 2

Describe the Potsdam Study (European Prospective Investigation into Cancer and Nutrition) - what were the key findings?

Answer 2

Prospective Cohort study - shows reduction in RR of developing chronic disease, associated with ‘healthy lifestyle factors’:
 never smoking
 BMI<30
 3.5+hrs/wk PA
 adhering to healthy diet
Having all 4 factors gives adjusted HR of 0.22 of developing chronic disease

Question 3

According to the Potsdam study, which healthy lifestyle factor lead to the biggest reduction in chronic disease

Answer 3

BMI associated with largest reduction (for any disease, diabetes, stroke)

Question 4

According to the Potsdam study, the risk of which chronic disease is most reduced by having all 4 healthy lifestyle factors (non-smoking, BMI, PA, diet)?

Answer 4

Diabetes, reduced by 93%

Question 5

What did the Healthy Lifestyle Heart trial (lead by Ornish in 1998) show?

Answer 5

In CHD, intensive lifestyle change (low fat vege diet, exercise, stop smoking, stress management/support)
resulted in reduction in stenoses (cf control group that increased) and approximately half the deaths, after 5 years.
There was a dose-response relationship between adherence and regression of stenoses

Question 6

When intensive lifestyle changes were compared in a RCT to metformin or placebo (as part of the Diabetes Prevention Program), what was more effective?

Answer 6

Findings: Lower cumulative incidence of diabetes in metformin (31%) and lifestyle groups (58%)
Lifestyle group significantly less diabetes than metformin.
NNT (lifestyle) 6.9 (over 3 years), NNT (metformin) 13.9

Question 6

What effect did the Healthy Lifestyle Heart trial (Ornish) show on cholesterol?

Answer 6

At 1 year demonstrated decreased LDL, angina episodes
LDL in intervention group similar to levels on lipid-lowering drugs

Question 7

What was the key finding of the PREDIMED study?

Answer 7

As primary prevention, Mediterranean diet with EVOO or nuts decreases risk of major CV events over 5 years: relative difference ~30%, absolute difference of 1.7-2.1%

Question 8

What was the key finding of the DASH Diet study?

Answer 8

Combination diet (high fruit/vege plus lowfat dairy) reduced BP significantly in those with and without hypertension, compared to control – independently of weight loss and PA, and not related to sodium intake.

Question 9

What is the evidence that lifestyle interventions can prevent cognitive decline in at-risk elderly people?

Answer 9

FINGER study: Parallel RCT in older adults at risk of Dementia
Intervention group received nutritional guidance (fruit/vege, whole grains, low fat milk/meat, fish and limiting sat fat/sugar), guided PA (strength, aerobic & balance), cognitive training & social activity, management of metabolic/vascular risk factors
After 2 years, cognitive decline (measured by neuropsychological test battery) was less in intervention group. OR 1.31 for control group
Key finding: multidomain intervention can maintain cognitive functioning in at-risk elderly

Question 10

What study has showed evidence that type 2 diabetes can be reversed?

Answer 10

Lim et al. Diabetologia 2011
Tested if dietary restriction of energy intake would normalise beta cell function and insulin sensitivity in people with type 2 diabetes
Matched intervention study of 8 weeks of 600kcal/day
Found blood glucose normalised within 1 week (normalised beta cell function and hepatic insulin sensitivity)

Question 11

What evidence is there that exercise can be as effective as stenting for CAD?

Answer 11

Hambrecht et al Circulation 2004
Compared exercise (20 min bike erg/day) to PCI in males with stable CAD.
At 12 months: exercise had higher event free survival, increased HDL (and higher VO2max, exercise tolerance and ischaemic threshold). Clinical symptoms improved in both groups, exercise was more cost-efficient

Question 12

Compare the outcomes after one year when given instructions (not intensive intervention) to follow an Atkins, Ornish, WeightWatchers or Zone diet?

Answer 12

Similar modest weight loss in all groups, no difference
Weight loss improved with adherence
All diets reduced LDL:HDL ratio
Weight loss from any diet associated with improved lipid ratio, CRP, insulin.