Change in pancreatic B-cell function (HOMA-B) varies in different populations with similar genetic backgrounds but different environments.
OBJECTIVE
To determine whether pancreatic B-cell function varies in different populations with similar genetic backgrounds but different environments.


METHODS
We compared a specific migrant Gujarati community in the UK (n = 205) with people still resident in the same villages of origin in Gujarat, India (n = 246). Pancreatic B-cell function (HOMA-B) was determined and the influence of age, migration and other factors was explored.


RESULTS
As anticipated, there was an age-related decline in log(HOMA-B) in both groups. However, the age-related fall in log(HOMA-B) was more pronounced in the UK than in Gujarat (normalized beta-0.29 vs. -0.14, P for difference = 0.03). The decline of HOMA-B with age persisted after adjustment for body mass index (UK beta = -0.31; Gujarat beta = -0.16, P = 0.015, P < 0.001). There was no significant change in insulin sensitivity (HOMA-S) with age at either site, although insulin sensitivity was lower in the UK. Fasting non-estrified fatty acid (NEFA) levels rose with age in the UK but not in Gujarat (P = 0.003 for difference in gradients). In multiple linear regression analysis, lower log(HOMA-B) was independently associated with higher fasting log(NEFA) levels; normalized beta = -0.24, P < 0.001, age; beta = -0.16, P = 0.005, higher log(insulin-like growth factor binding protein-1); beta = -0.19, P = 0.007 and lower body mass index; beta = 0.26, P = 0.001. This model accounted for 25% of the variability in HOMA-B.


CONCLUSIONS
HOMA-B as a measure of B-cell function declines more rapidly with age in the migrant UK group than in Gujarat. This may be a direct consequence of chronically higher NEFA exposure in the UK group.
Heald
A H
AH
Department of Diabetes & Endocrinology, Univerity of Manchester, Salford NHS Trust, Hope Hospital, Salford, Greater Manchester, UK. aheald@fs1.ho.man.ac.uk
Anderson
S G
SG
Patel
J
J
Rudenski
A
A
Vyas
A
A
Yates
A
A
Hughes
E
E
Prabharakan
D
D
Reddy
S
S
Durrington
P
P
Gibson
J M
JM
Bhatnagar
D
D
Cruickshank
J K
JK
Laing
I
I
D000367:Age Factors; D000596:Amino Acids / Q000502:physiology; D015992:Body Mass Index; D002857:Chromium / Q000502:physiology; D004641:Emigration and Immigration; D004739:England / Q000208:ethnology; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005260:Female; D006801:Humans; D007194:India / Q000208:ethnology; D050417:Insulin-Secreting Cells / Q000502:physiology*; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009539:Nicotinic Acids / Q000502:physiology
D000596:Amino Acids; D005230:Fatty Acids, Nonesterified; D009539:Nicotinic Acids; C015240:glucose tolerance factor; D002857:Chromium