1 - Metabolic Syndrome

Question 1

What are the main features of metabolic syndrome? (2012 Q1a, 2m)
What are the aspects of metabolic syndrome that the different definitions provided by the different organisations (WHO, NCEP, IDF) agree on?
Hint: 4

Answer 1

1. obesity
2. insulin resistance / glucose intolerance
3. hypertension
4. dislypidaemia

Question 2

Re: IDF’s definition of a metabolic syndrome

What are the specifications of the mandatory component?

Answer 2

CENTRAL OBESITY: waist circumference

• Europid: ≥ 94cm (M), ≥ 80cm (W)
• Asian: ≥ 90cm (M), ≥ 80cm (W)
• Japanese: ≥ 85cm (M), ≥ 90cm (W) (new data suggest using Asian values for Japs anyway)

Question 3

Re: IDF’s definition of a metabolic syndrome
What are the ‘other’ non-mandatory criteria and their specifics, and how many must be met?
Hint: 4

Answer 3

At least 2 of the following:

• TG: >1.7mmol/L or on specific treatment
• HDL:

Question 4

Draw the flowchart of the proposed hypothesis regarding the aetiology of metabolic syndrome

Answer 4

Refer to L1S17

Main idea: obesity is the main cause

Question 5

Insulin is used to regulate blood glucose. What are the other ‘side’ effects it has on patients, with regards to metabolic syndrome?
Hint: 2

Answer 5

1. weight gain

2. hypertension

Question 6

How does insulin cause hypertension?

Answer 6

Insulin stimulates sodium reabsorption in the kidneys which in turn increases water retention, increasing blood volume and hence results in higher-than-normal- blood pressures.

Question 7

What were the properties investigated in the PEPCK KO mice, and in what way did they respond differently?

Answer 7

Same body weight but increased body fat weight
Fasting TG levels didn’t change at 3mths old but only at 6 mths
Increased cholesterol levels maintained through 3-6 mths
Same FBG levels but hyperinsulinemia, significant insulin resistance & cytokine production
Significantly increased 11B HSD-1 in adipose tisuse
Same MAPK activation but significantly decreased PI3K activation

Question 8

How is the PEPCK enzyme different to the other 2 main enzymes involved in gluconeogenesis? Why was it chosen to be involved in the transgenic mice experiment investigating glucose toxicity?

Answer 8

Out of the 3 enzymes, it is the only one whose activity is regulated at the gene level

Question 9

“The prevalence of obesity & the incidence of metabolic syndrome have both increased steeply since the 1960s. Identify social & environmental factors that have been implicated in these increases.” (2013 Q2, of 10m)

Answer 9

1. income disparity
2. decreased activity levels (caused by obesity,)
3. increased caloric intake (reduced prices -> increased affordability & availability of food)
   CHECK IF THERE’S MORE
   NOT: epigenetics