Low-income people with diabetes are significantly more likely to be admitted to a hospital for hypoglycemia — a potentially dangerous medical condition marked by abnormally low levels of blood sugar — at the end of the month than at the beginning, a new study has found.

Hypoglycemia-related hospital admissions for higher-income people with diabetes, on the other hand, were found to remain constant throughout the month.

These findings suggest, say the study’s authors, that hospital admissions for hypoglycemia among the poor are related to the exhaustion of household food budgets late in the month.

Hypoglycemia occurs when people with diabetes continue to take medication to control their blood sugar levels, but reduce the amount of food they eat. As a result, blood sugar levels plummet, causing such symptoms as sweating, nausea and mental confusion. Severe cases can lead to coma and even death.

The U.S. rate of type 2 diabetes has risen dramatically in recent years, and low-income Americans have been disproportionally affected. In addition, more than 33 million American adults — or one in seven U.S. households — cannot reliably afford food, particularly at the end of the month. (Supplemental Nutrition Assistance Program, or SNAP, benefits, for example, tend to last only two to three weeks.)

The number of households with insufficient resources for food is expected to rise in 2014 as a result of recent congressional cuts in various government assistance programs, including SNAP (formerly known as food stamps) and unemployment benefits.

Methods and findings

For the study, researchers at the University of California, San Francisco, examined hospital admission records for all adults (aged 18 and older) admitted to California hospitals for hypoglycemia during the years 2000 through 2008. As a control, the researchers also looked at admissions data for appendicitis, an illness not affected by the quantity of food consumed.

The patients’ ZIP codes were then matched to the admission records. Individuals who lived in ZIP codes where the average household income was $31,000 or less were considered low income.

An analysis of the data found that 270 of every 100,000 low-income people admitted to a hospital received a primary diagnosis of hypoglycemia. That compared with a rate of 200 per 100,000 among people with higher incomes.

The data also revealed that the monthly patterns of those admissions differed significantly between low- and high-income patients. Among low-income patients, hospital admissions attributable to hypoglycemia rose from 240 per 100,000 total admissions during the first week of the month to 300 per 100,000 in the fourth week — an increase of 27 percent.

Among high-income patients, however, the rate of admissions attributable to hypoglycemia was the same in the fourth week as it was in the first week: 200 per 100,000 total admissions.

The data also found that the rate of admissions for appendicitis remained stable throughout the month for people in both income groups.

‘An important driver of health inequities’

This was an observational study, so its findings cannot prove that exhausted household food budgets are why the risk for hyperglycemia tended to rise among low-income Californians toward the end of each month.

But the finding that the higher end-of-the-month risk of hypoglycemia occurred only among the low-income population — as well as findings from other studies that have shown that people with diabetes who are hungry or at risk of being hungry are two to three times more likely to report episodes of severe hypoglycemia — strongly suggests that stressed food budgets played a role, say the study’s authors.

Those stressed budgets may also influence hospital-admission patterns for other diseases sensitive to diet, such as congestive heart failure, the researchers add.

“The exhaustion of food budgets the end of the month could be an important driver of health inequities,” the study’s authors write. “Policy solutions could include improving stable access to nutrition throughout the month for people with limited incomes and raising awareness of the health risks of food insecurity.”

The study was published Monday in the journal Health Affairs.