org355: 'Alarming’ rise in type 2 diabetes

From The Guardian

The UK ranks among the worst in Europe with the most overweight and obese adults, according to the World Health Organization. On obesity rates alone, the UK is third after Turkey and Malta.

1. What epidemiologic statistic do you think the WHO used to rank countries?

There is a seven times greater risk of type 2 diabetes in obese people compared with those of healthy weight, and a threefold increase in risk for those just overweight.

2. What is the value of the relative risk (RR) figures estimated here? Who are in the denominators and the numerators? What is the specific name for this RR?

3. (For returning students) What sort of epidemiologic study design was most likely used to estimate these RRs? Why was this design more likely than the others?

The number of people under 40 in the UK diagnosed with type 2 diabetes has jumped 23% from about 120,000 in 2016/17 to 148,000 in 2020/21, according to Diabetes UK.

4. Are these incidence or prevalence figures? (NB: I'm actually not sure myself!)

5. What are some possible explanations for the increase over time?

Bonus article! From FT.

In July, a US study found that taking a single dose of doxycycline within 72 hours of having sex without using a condom reduced the risk of contracting syphilis, chlamydia and gonorrhoea by more than 60 per cent among people at high risk of contracting sexually transmitted infections.

6. What is the value of the relative risk (RR) figure estimated here? What is the specific name for this RR?

7. PICO: Who was eligible for the study (Population)? What was the Intervention? The Control? And the Outcome?

Re: 'Alarming’ rise in type 2 diabetes

by | NICOL REDZO - Thursday, 3 November 2022, 1:39 PM

Dear Sujit and everyone

Find my thinking on this article. I found this challenging though.

1. What epidemiologic statistic do you think the WHO used to rank countries?

There is a seven times greater risk of type 2 diabetes in obese people compared with those of healthy weight, and a threefold increase in risk for those just overweight.

Answer:

Risk ratio using healthy weight as reference group.

2. What is the value of the relative risk (RR) figures estimated here? Who are in the denominators and the numerators? What is the specific name for this RR?

Answer:

· The value of RR(obese) is 7.0 and RR(overweight)=4.0

· Denominators (Healthy weight group who developed type 2 diabetes)

· Numerators (obese or overweight groups who developed type 2 diabetes)

· Risk ratio because we are comparing those obese or overweight with the health weight to assess the risk of developing type 2 diabetes

3. (For returning students) What sort of epidemiologic study design was most likely used to estimate these RRs? Why was this design more likely than the others?

The number of people under 40 in the UK diagnosed with type 2 diabetes has jumped 23% from about 120,000 in 2016/17 to 148,000 in 2020/21, according to Diabetes UK.

Answer:

Prospective Cohort study design. The study population did not have type 2 diabetes at the start of the study in 2016 but was evaluated for the occurrence of the type 2 diabetes during the study period 2016 to 2021.The design was ideal to establish clear causal association between exposure and outcome (type 2 diabetes). If a case-control design was used it was going to be difficult to establish if diabetes was as result of a certain body weight or the body weight was as a consequence of the diabetes .

4. Are these incidence or prevalence figures? (NB: I'm actually not sure myself!)

Answer:

These are incidence figures because where starting with a group that is disease free which is followed up overtime to evaluate the occurrence of diabetes.

5. What are some possible explanations for the increase over time?

Answer:

-Diabetes is a chronic conditions and in a stable population where those with the disease are not dying the only direction is increase in disease prevalence if people develop the disease.

Bonus article! From FT.

6. What is the value of the relative risk (RR) figure estimated here? What is the specific name for this RR?

Answer:

Value of RR=1.60

Name of the RR= Risk ratio

7. PICO: Who was eligible for the study (Population)? What was the Intervention? The Control? And the Outcome?

Answer:

Population: Adult population at high risk of contracting sexually transmitted infections.

Intervention: exposure to doxycycline within 72 hours of unprotected sex.

Control: non exposed to doxycycline

Outcome: syphilis, chlamydia and gonorrhoea

regards Nicol

Re: 'Alarming’ rise in type 2 diabetes

by | Monica Mtei - Friday, 4 November 2022, 9:16 AM

Hi Sujid,

1. I think they have used prevalence to rank the countries

2. I am not sure maybe 2. The first numerator is new cases of type 2 diabetes and the denominator is the population at risk(obese and healthy). The second numerator is new cases of type 2 diabetes and the denominator is (obese, just overweight and healthy). The name given to it is the Risk ratio

3. Study design to estimate the RR here is a prospective cohort

4. Prevalence figures because they are taken as existing cases at a specific time period. If they were incidence cases it would have been new cases

5. Prevalence is affected by the duration of the disease hence those with the disease longer will tend to increase the number. Other factors that could have increased are immigration, new incident cases added to the pool of existing(prevalent) cases, and good quality of care of cases which make them survive longer.

Those are my thoughts.

Best wishes,

Monica

Re: 'Alarming’ rise in type 2 diabetes

by | RANMINI SUMUDITA KULARATNE - Sunday, 6 November 2022, 6:10 AM

1. Obesity index - ranking countries by prevalence of obesity in adults and children (using BMI and weight for height indicators etc)

2. "seven times greater risk of type 2 diabetes in obese people compared with those of healthy weight": Incidence risk 1: numerator = number of new type 2 diabetes cases in obese population; denominator = total number of obese persons at risk at beginning of period. Incidence risk 2: numerator = number of new type 2 diabetes cases in normal weight population; denominator = total number of normal weight persons at risk at beginning of period.
Incidence risk ratio = Incidence risk 1/ Incidence risk 2 = 7.0

"threefold increase in risk for those just overweight" Incidence risk 1: numerator = number of new type 2 diabetes cases in overweight population; denominator = total number of overweight persons at risk at beginning of period. Incidence risk 2: numerator = number of new type 2 diabetes cases in normal weight population; denominator = total number of normal weight persons at risk at beginning of period.
Incidence risk ratio = Incidence risk 1/ Incidence risk 2 = 3.0

3. Historical cohort design (where exposure (BMI) documented before outcome) - more convenient, no need for longterm follow up

4. Prevalence figures (period prevalence)

5. Sedentary lifestyle; unhealthy diet; stress; genetic factors (perhaps greater number of immigrants) and other environmental factors

6. RR < 0.4 Incidence risk ratio. Strategy likely to be less effective in regions where the prevalence of tetracycline resistance in N. gonorrhoeae is high (>90% in some countries).

7. Population: at-risk persons having sex without condom; Intervention: single dose of doxycycline within 72 hours of having sex; Comparator: no doxycycline use; Outcome: new cases of STI (syphilis, chlamydia, gonorrhoea) within a defined period of time after exposure to risk.

Re: 'Alarming’ rise in type 2 diabetes

by | JUDITH MARGARET BURCHARDT - Sunday, 6 November 2022, 10:18 AM

The UK ranks among the worst in Europe with the most overweight and obese adults, according to the World Health Organization. On obesity rates alone, the UK is third after Turkey and Malta.

1. What epidemiologic statistic do you think the WHO used to rank countries?

I imagine it was the percentage prevalence of obesity in the adult population. This will not have been adjusted for age.

There is a seven times greater risk of type 2 diabetes in obese people compared with those of healthy weight, and a threefold increase in risk for those just overweight.

2. What is the value of the relative risk (RR) figures estimated here? Who are in the denominators and the numerators? What is the specific name for this RR?

This sounds like a prevalence risk ratio. People are divided into three BMI categories - obese, overweight and normal.

For the obesity prevalence risk ratio - The numerator is the number of people obese with diabetes/total number of obese people. The denominator is the number of people normal weight with diabetes/total number of normal weight people.

For the overweight prevalence risk ratio - The numerator is the number of people overwieight with diabetes/total number of overweight people. The denominator is the number of people normal weight with diabetes/total number of normal weight people.

3. (For returning students) What sort of epidemiologic study design was most likely used to estimate these RRs? Why was this design more likely than the others?

Ecological study - cheaper to do as uses routinely collected data

The number of people under 40 in the UK diagnosed with type 2 diabetes has jumped 23% from about 120,000 in 2016/17 to 148,000 in 2020/21, according to Diabetes UK.

4. Are these incidence or prevalence figures? (NB: I'm actually not sure myself!)

Imagine prevalence, as usually incidence is stated. Also we know that the incidence of diabetes is thankfully not 23% in people under 40.

5. What are some possible explanations for the increase over time?

An increase in population size.
A change in the age profile of the population with people under 40 being older on average in 2020/1 than in 2016/7
An increase in risk factors for diabetes - obesity, ethnicity, lack of physical exercise, covid-related lifestyle changes, covid itself (not sure about this, think I read it somewhere)
Thank you Monica for reminding me about increased survival as always being something to think about in prevalence studies.
Bonus article! From FT.

In July, a US study found that taking a single dose of doxycycline within 72 hours of having sex without using a condom reduced the risk of contracting syphilis, chlamydia and gonorrhoea by more than 60 per cent among people at high risk of contracting sexually transmitted infections.

6. What is the value of the relative risk (RR) figure estimated here? What is the specific name for this RR?

40%. Incidence rate ratio

7. PICO: Who was eligible for the study (Population)? What was the Intervention? The Control? And the Outcome?

P: people at high risk of STI who had sex without a condom
I: doxycycline within 72h of SI
C: good question! I don't subscribe to the FT so can't read the article. If this were observational rather than a randomised trial then it would be likely to be confounded by characteristics associated with the choice of the person to not take the doxycycline. (education etc)
O: new case of STI (syphilis, chlamydia, gonorrhoea) within a defined time

Re: 'Alarming’ rise in type 2 diabetes

by | MAR ESTUPINAN FERNANDEZ DE MESA - Sunday, 13 November 2022, 9:44 PM

1. What epidemiologic statistic do you think the WHO used to rank countries?

A measure of disease frequency and disease burden such as prevalence of obesity and overweight. This measures the proportion of individuals who are obese and overweight in a defined population at a specified point in time.

There is a seven times greater risk of type 2 diabetes in obese people compared with those of healthy weight, and a threefold increase in risk for those just overweight.

2. What is the value of the relative risk (RR) figures estimated here? Who are in the denominators and the numerators? What is the specific name for this RR?

RR = 7.0 for obese people and threefold increase in risk for those just overweight.

Numerator = RR exp = Obese-overweight people with diabetes/ Obese-overweight people w/o diabetes

Denominator = RR non-expose = non-obese/overweight with diabetes/ non-obese overweight w/o diabetes

Relative risk (risk ratio) which is a measure of effect. It measures the strength of the association between and exposure and a disease and can be used to assess whether a valid observed association is likely to be causal.

3. (For returning students) What sort of epidemiologic study design was most likely used to estimate these RRs? Why was this design more likely than the others?

Cohort observational study because it allows to follow up a group of people during a period of time to study the occurrence of a disease and allows to examine associations and identify the causes of the outcome. In this case, researchers would have followed people who didn’t have diabetes at the start of the study and followed them up over a period of time to study if participants develop the disease.

The number of people under 40 in the UK diagnosed with type 2 diabetes has jumped 23% from about 120,000 in 2016/17 to 148,000 in 2020/21, according to Diabetes UK.

4. Are these incidence or prevalence figures? (NB: I'm actually not sure myself!)

Probably prevalence because these figures would include the existing cases plus the new cases of diabetes.

5. What are some possible explanations for the increase over time?

More sedentarism, people accessing processed food, obesogenic environments leading to an increase in obesity and overweight which are risk factors to develop diabetes.