The first rule of statistics is that correlation does not imply causation, but don't tell that to Chelsea Clinton. The former First Daughter has taken to Twitter, yet again, to share "horrifying" research that links climate change to obesity, and hence, to Type 2 diabetes.
The study, written about in The LA Times earlier this week, posits that global warming could lead to an additional "100,000 diabetes cases" per year in the U.S. alone:
[...] People develop type 2 diabetes when their extra pounds and sedentary lifestyle make their bodies less sensitive to insulin. That, in turn, causes their blood sugar to rise and can eventually lead to heart disease, nerve damage, kidney problems and other serious health issues.
Researchers thought they might find a link between rising temperatures and diabetes for a completely different reason — the activity of brown fat.
Also known as brown adipose tissue, or BAT, this fat kicks into gear when temperatures are low and the body needs heat to stay warm.
A 2015 study of eight adults with Type 2 diabetes found that after spending 10 days in moderately cold weather, their metabolisms improved and they became more sensitive to insulin, reversing a key symptom of the disease.
A 2016 study found a correlation between outside temperature and a measure of blood sugar called HbA1c — when the first was higher, so was the second.
Findings like these led Dutch researchers to wonder whether climate change could explain some of the worldwide increase in diabetes. Back in 1980, 108 million adults had the disease; by 2014, that figure was 422 million, according to the World Health Organization.
The researchers turned to the U.S. Centers for Disease Control and Prevention to gather data on the prevalence of diabetes in all 50 states for each year between 1996 and 2013. They also found the average temperature for each state in each year from the National Centers for Environmental Information.
Of course this couldn't have anything to do with changes in our daily habits. People across the world, not just in the U.S., now regularly consume processed foods and high fructose corn syrup while at the same time leading more sedentary lifestyles (due to the advent of the personal/work computer). Never mind that.
Eight people gave the True Believers hope that, when it comes to global warming, the correlations are endless:
...as the annual average temperature rose by 1 degree Celsius (or 1.8 degrees Fahrenheit), the number of diabetes cases rose by 3.1 per 10,000 people.
Obesity is a risk factor for Type 2 diabetes, and the researchers also found that each 1-degree Celsius temperature increase was associated with a 0.173% increase in the prevalence of obesity.
Even when the researchers adjusted for the prevalence of obesity in each state, they found that each 1-degree temperature increase was associated with 2.9 additional cases of diabetes per 10,000 people. [...] The results were published Monday in the journal BMJ Open Diabetes Research & Care.
But that would assume it is a fact that average annual temperatures rise to at least the degree cited in the study, consistently each year, and because of global warming. It also discounts the myriad other factors that might also correlate with less-than-three additional diabetes cases per 10,000 people per year.
Again, correlation does not prove causation. But to be on the safe side, maybe we should alert Wilford Brimley.