Robin and Kurt graze May 1, 2016. The heat and humidity of 2016 nearly killed these two laminitic horses.

Post reviewed Nov. 26, 2022

There are many theories as to what is driving the insulin-resistant form of laminitis to record highs. The answer may be rising temperatures.

Researchers from The Netherlands published a study in March 2017 linking human diabetes to increased outdoor temperatures.

The researchers concluded that a 1 degree Celsius rise in temperature could account for more than 100,000 new diabetes cases in humans per year in the U.S. alone. The study appeared in the open access journal BMJ Open Diabetes Research & Care.

Laminitis is on the rise throughout the world, according to many sources. Equine veterinarians repeatedly have chosen laminitis as their biggest challenge on surveys. And an annual U.K. equine survey estimated in 2016 that laminitis ranked second in equine illnesses in the country, behind lameness in general, and accounted for 6.8 percent of illness.

The insulin form of laminitis far outpaces other forms of the disease.

The Netherlands study authors took note of recent data showing that patients with type 2 diabetes who were exposed to moderate cold for only 10 days improved insulin sensitivity. They attributed this improvement to cold exposure activating brown adipose tissue, which combusts large amount of lipids to generate heat.

The researchers described their study as the first to assess the association of outdoor temperature with diabetes incidence and the prevalence of raised fasting blood glucose on a national and global level. They used 14-year longitudinal state-level data from the U.S. and showed the overall diabetes incidence rate is higher in warmer years. For each 1 degree Celsius increase in temperature, they found an overall increase in diabetes incidence of 0.314 per 1,000.

NASA reported Jan. 18 that the Earth’s 2016 surface temperatures were the warmest since modern recordkeeping began in 1880. Globally averaged temperatures in 2016 were 1.78 degrees Fahrenheit (0.99 degrees Celsius) warmer than the mid-20th century mean. This makes 2016 the third year in a row to set a new record for global average surface temperatures, NASA said.

At the end of the summer of 2016, an unbearably hot summer that took a big toll on my two laminitic horses, I looked at what the future holds for my location near St. Louis, Missouri, according to two groups of scientists.

By 2030 (not so far away), St. Louis will have 46 days with a heat index above 105 degrees, a sharp increase from the total of 12 days in 2000, according to Climate Central. That’s a month and a half of dangerous weather. By 2050, the number will jump to 63.

Florida, Texas and Arizona are looking at even bigger increases. McAllen, Texas, will have 179 days (more than half a year) at that level by 2050, the group says.

By 2100, St. Louis’ average summer high will be 96.69 degrees, up from the current average of 86.85 degrees, a terrifying jump.

Climate Central looked at summer temperatures since 1970 and based its projections on current greenhouse gas emissions trends continuing.

The Union of Concerned Scientists looked at weather changes in St. Louis from 1946 to 2011.

Among its findings: On very hot, humid nights, the temperature rose 2.1 degrees and the dew point increased .6 degrees.

On hot, dry nights, the temperature increased 4.4 degrees and the dew point increased 7.7 degrees. Not sure why those would be still be called “dry” nights.

As for humans and diabetes, currently, more than 34 million Americans have diabetes, and one in four doesn’t know it, according to the Centers for Disease Prevention and Control. Another 88 million Americans have pre-diabetes.