Diabetic blood sugar control: An urban/rural comparison

Introduction

Bella Coola is a rural, remote community located in northwestern British Columbia. The closest referral hospital, in Williams Lake, is more than 450 km by road; the closest tertiary-care centre is in Vancouver, a 2-hour flight. The hospital in this community is one of the 10 most isolated physician-staffed health facilities in British Columbia (Table 1).[1] The Northern Isolation Allowance (NIA) score—a measure of community rurality—for Bella Coola is 130. Only Dease Lake and New Aiyansh have higher NIA scores, but neither has a fully staffed hospital like Bella Coola’s. The physicians working in Bella Coola serve an estimated clinic population of 2750 people.[2] Each year these physicians see more than 8000 patients in the clinic and 2500 patients in emergency, admit 400 patients to hospital, and deliver 20 to 30 babies.[3] Bella Coola is also a rural training site for University of British Columbia’s Family Physician Residency Program.

Bella Coola is one of five communities located in the Cariboo region that has a physician-staffed health facility (Table 2). The Cariboo region is known to be among the unhealthiest regions not only in British Columbia, but in all of Canada.[4,5] In the provincial health officer’s annual report for 1996, for example, the age standardized mortality rates for the Cariboo Health Region* (53.0/10 000 standard population) was almost one-and-a-half times that of health regions in the Lower Mainland (e.g., in the Richmond Health Region* it was 39.8/10 000 standard population).[5] The provincial health officer believes that these health region inequities are due mainly to differences in socioeconomic conditions.[5] Other factors may also play a role. Relative lack of specialists and low long-term family physician retention rates (lack of physician continuity) are also associated with poor health in these health regions.[6-8]

* The BC government reorganized the health regions into health authorities and health service delivery areas in April 2002, but these older terms have been retained because they reflect the data discussed in this article.

The poor health reported for northern health regions may also be due to the greater percentage of aboriginal people who live in these areas.[2,6] Native people in British Columbia, across Canada, and across North America have more health problems per capita—both physical and psychosocial—than non-native people.[5,9-11] Looking at mortality rates, for example, the infant death rate for aboriginals is over twice that for all of Canada; the death rate from injury and poisonings is four times the Canadian average; the suicide rate among 15- to 19-year-old natives is six times the Canadian rate; and death from diabetes is six times the Canadian average.[5,9,12-15]

Diabetes mellitus type II is now a leading cause of death, illness, and disability across North America. It affects an estimated 18 million North Americans and 1.5 million Canadians.[16-18] Having diabetes substantially increases the risk of an adult developing blindness, end stage renal disease, and lower limb amputations, and increases the risk of dying from coronary artery disease, stroke, or peripheral vascular disease.[19,20]

Diabetes treatment guidelines

Recent studies have shown that keeping blood sugar levels within normal range reduces the chances of developing at least some of the complications associated with having diabetes.[21-24] Consequently, the mainstay of diabetes type II treatment is now currently focused on achieving better glucose control through diet, exercise, and medications.[25-29][16,24] Initial and ongoing education of the patient with diabetes should be an integral part of diabetes management and not merely an adjunct to treatment. Whenever possible, diabetic patients should receive dietary advice from a registered dietitian. If adequate blood sugar levels have not been reached on a regimen that includes appropriate use of diet, exercise, and oral agents, then insulin therapy should be initiated to improve diabetic control.[16] According to the United Kingdom Prospective Diabetes Study (UKPDS), intensive insulin therapy prevents microvascular complications in patients with diabetes type II.[22][30] A prospective study showed that insulin treatment improves glycemia for a long period (9 years) in normal weight and moderately obese patients who develop secondary failure to oral hypoglycemic agents.[31] Two studies go one step further to recommend early use of insulin for patients with diabetes type II when non-drug therapies fail to achieve individual goals. Their rationale is that if insulin is started early enough, endogenous insulin secretion might transiently or partly recover, reducing overall insulin requirements.[30,32,33] According to Canadian and American practice guidelines, glycosylated hemoglobin (HgA_Ic)—a laboratory blood test—should be measured every 3 to 4 months in all patients taking insulin and at least every 6 months in people on nutrition therapy and/or oral hypoglycemic agents. Recent evidence support that near normalization of HgA_Ic levels (<7.0 – 7.5) represents a rational goal for younger type II diabetic patients (<65 year of age). For patients older than 65 years, prevention of diabetes-related symptoms becomes the main therapeutic goal.

In British Columbia there are about 80 fully accredited diabetes teaching centres (Table 3 and Table 4) that provide education and support to people with diabetes, their families, and their friends. These diabetes teaching centres are also referred to as diabetes education centres. Most are staffed by nurses and dietitians, as well as other health professionals—including physicians.[34,35] Isolated rural communities such as Bella Coola lack the volume of patients and the number of health professionals (e.g., dietitians) required to run a fully accredited diabetes education centre. In Bella Coola, a nurse practitioner sees the diabetics and reviews diet, while physicians typically review whether the recommended diabetes monitoring guidelines are being followed.

Urban/rural treatment differences?

In an attempt to see whether diabetics living in an isolated rural community have poorer blood sugar control compared with diabetics attending an urban family practice clinic—who would have easier access to a diabetes education centre—we compared glycosylated hemoglobin (HgA_Ic) values and diabetic care received by Bella Coola diabetics to diabetics attending a University of British Columbia family practice clinic located in Vancouver (the Family Practice Teaching Unit on Fairview Avenue). The questions we are trying to answer through these data are:

• Are there differences in HgA_Ic values between the two sites? 

• What percentage of patients with HgA_Ic values 0.08 are on insulin at the two sites?

• Did referring the patient to a diabetic teaching program, which includes endocrine assessment, result in lower levels of HgA_Ic?

Methods

Two lists of diabetes mellitus type II patients were compiled. One list included all the known diabetics attending a rural family practice site (Bella Coola Medical Clinic); the second list included all the known diabetics attending two urban family practice sites (UBC Family Practice Teaching Units). Patients with diabetes mellitus type I were excluded from this study. There were 85 known diabetics attending the rural family practice clinic, and 79 known diabetics attending the urban family practice clinic. Charts were reviewed retrospectively for the following:

• Date and value of most recent HgA_Ic.

• Whether the patient received diabetic education.

• Details of patient’s management: diet, hypoglycemic, or insulin.

• Whether the patient was referred to a diabetic teaching centre, where a visit typically consists of 3 days of intensive diabetic teaching and an endocrine consultation.

Results/discussion

There is no gender difference between the two sites (Table 5). The mean age of Vancouver diabetics (64.5 ± 13 years) was significantly greater (P <0.01) than the mean age of the Bella Coola diabetics (59.2 ± 11 years). This finding is consistent with the 1996 census report that gives the percentage of population older than 64 years as 7% for the Bella Coola Valley and 13% for the Vancouver Health Region.[2] More of the urban diabetics (88.6%) had an HgA_Ic value collected within the past 6 months (P <0.05) as compared to the rural diabetics (65.9%). In both the urban and rural diabetic groups, having an HgA_Ic done in the last 6 months was not related to the type of treatment (i.e., insulin, oral hypoglycemics, or diet modifications), whether the patient received a consultation or diabetic education. The use of timely reminders for diabetic assessment and management is something both rural and urban clinics may wish to consider, particularly for following diabetics taking insulin.

Within the Bella Coola diabetic group, a significant relationship was found between patients with HgA_Ic0.08 and being on insulin (P = 0.03), being on an oral hypoglycemic (P<0.002), and being referred for consultation and attending diabetic teaching centres in Vancouver (P = 0.0075). There was no relationship between patients with HgA_Ic 0.08 and receiving diabetic education, presumably because all the diabetics in this group received diabetic education.

Within the urban diabetic group there was no statistically significant relationship between patients with HgA_Ic0.08 and being started on insulin (P = 0.051), being on an oral hypoglycemic (P = 0.86), being referred for consultation (P = 0.13), or receiving diabetic education (P = 0.82). The lack of correlation between patients having HgA_Ic 0.08 and being on insulin may simply reflect the fact that the patients were started on insulin in the distant past and blood sugar control improved over time. Lack of correlation between patients having HgA_Ic 0.08 and referral to an endocrinologist reflects the fact that urban family physicians are more likely to refer all their diabetics to a diabetic teaching centre than are rural family physicians.

Bella Coola diabetics received more clinic-based diabetic education than did the Vancouver diabetics (P <0.01). This is probably due to the presence of a public health nurse at the Bella Coola Medical Clinic who is actively involved in providing diabetic education to patients at the time of their diagnosis and periodically thereafter. Urban diabetics were more likely (P = 0.01) to have been referred to a diabetic teaching centre and had an endocrine consultation when compared with the rural diabetics. The lower percentage of rural diabetics being referred for consultation at a diabetic teaching centre probably reflects the fact that rural diabetics must travel greater distances, spend more money, and make a greater time commitment than their urban counterparts.

Despite the differences in diabetic care between the two groups, there was no significant difference in mean HgA_Ic values or in the proportion of diabetic patients recording HgA_Ic values 0.08 between the two sites (Table 5). However, when HgA_Ic values are divided into categories, more of the rural diabetics had an HgA_Ic value of <0.06 compared with the urban diabetics. While nearly one-third of the patients in both groups have an HgA_Ic value 0.08, only a few of these patients (8 out of 30 in Bella Coola and 6 out of 26 in Vancouver) are on insulin. Diabetics attending the UBC Family Practice Teaching Unit were significantly more likely (P <0.03) to be taking oral hypoglycemics compared with diabetics attending the Bella Coola Medical Clinic, who were more likely to be managed by diet and exercise.

Both clinics appear to have a conservative approach toward using insulin in patients with suboptimal control (i.e., HgA_Ic value0.08). Based on the previously mentioned studies, near normal glycemic control is a reasonable goal and insulin should be used whenever oral hypoglycemics fail to achieve the target HgA_Ic value.

Limitations

The two patient populations are not strictly comparable in that people living in Bella Coola Valley tend to be younger than their Vancouver counterparts. Also, proportionately more First Nations people live in the Bella Coola Valley (40% of the population) as compared with the Greater Vancouver region (2% of the population). A detailed profile of the Bella Coola diabetic population—age, sex, ethnicity, nutrition recalls, quality of life scores, complication rates—is being put together in the hope we can better understand the role of these factors in this rural diabetic patient population.

Conclusion

Despite the fact that diabetics living in the rural and isolated community of Bella Coola are referred less frequently to diabetic treatment centres and endocrinologists when compared with diabetics attending an urban family practice clinic in Vancouver, there was no significant difference between the two sites in mean HgA_Ic values, in the proportion of diabetic patients recording HgA_Ic values 0.08, or in the proportion of diabetics on insulin. If these results can be generalized to other rural communities in the Cariboo region, it would appear that the poor health reported for this region is not due to inferior management of diabetics.

Competing interests

None declared.

Table 1. Ten most isolated physician-staffed health facilities in BC.

DTC = Diagnostic and treatment centre FFS = Fee for service

Table 2. Physician-staffed health facilities in Cariboo region.

*From the College of Physicians and Surgeons' 2000-2001 Medical Directory

Table 3. Diabetes education centres in British Columbia accepting self-referrals.

For more information, please contact the Diabetes Resource Centre, Canadian Diabetes Association, 360 - 1385 West 8th Avenue, Vancouver, BC, V6H 3V9. 1 800 268-4656, info@bc.diabetes.ca.

Table 4. Diabetes centres requiring a doctor's referral.

Table 5. Statistical analysis comparing Bella Coola Clinic and UBC Clinic.

Marcos Gobrial, MD, CCFP, Hany Mekael, MD, CCFP, Nancy Anderson, MD, CCFP, Dieter Ayers, MSc, and Harvey V. Thommasen, MD, CCFP

Drs Gobrial and Mekael were family practice residents in the Department of Family Practice at the University of British Columbia and are currently medical officers in the Canadian Forces. Dr Anderson is an assistant clinical professor in the Department of Family Practice at UBC. Mr Ayers is a statistical consultant at the University of Northern British Columbia. Dr Thommasen is professor and chair of Community Health in the Faculty of Health and Human Sciences, University of Northern British Columbia, Prince George, BC.